Delayed menstruation with a negative pregnancy test: causes, consequences, what to do

What is a pregnancy test and how does it work?

Pregnancy tests detect the presence of human chorionic gonadotropin (hCG) in a woman's urine or blood. This hormone begins to be actively produced by the membranes of the embryo 6-8 days after fertilization. It is during this time that the egg penetrates the walls of the uterus. In a non-pregnant woman, the normal level of the hormone is below 5 mIU/ml and tests do not respond to it. As soon as a woman begins to bear the future fetus, the concentration of the substance begins to increase sharply, to which tests respond with a positive result.

Can a pregnancy test be wrong? Why does the test not show pregnancy if there is a delay?

The test may not show pregnancy if the period is too short and the hCG has not had time to rise to the sensitivity threshold of the test. You may be pregnant, but have incorrectly determined your ovulation date. In some cycles, ovulation may not occur in the middle of the cycle, as usual, but, for example, on the 18th day. The period at which the embryo attaches to the endometrium may also vary. This is why it is so difficult to determine how many days later to take a pregnancy test.

With late ovulation and late implantation of the embryo, hCG will reach a value of 15-20 mIU/ml only on the 33rd day, which in a 28-day cycle is equal to the 5th day of delay. If you think that pregnancy is possible with a negative test, repeat the test or donate blood for hCG.

What types of pregnancy tests are available?

There are 2 main types of pregnancy tests: urine and blood tests. Urine testing is the most practical and convenient because it can be performed at home. In pharmacy chains and on supermarket shelves you can see a wide variety of testers in different price categories. They differ in their level of sensitivity to hCG.

The more expensive ones react to relatively low levels of increased hormone levels (10 mIU/ml), and, therefore, make it possible to clarify the fact of motherhood at an earlier date - 7 days after conception (5 days before the delay). You should expect a positive result from cheaper testers from 1-3 days of missed period, when the concentration of the hormone in the urine is at least 25 mIU/ml.

Pregnancy tests also differ in how they are used:

• test strips. They are the most popular option to use. They are impregnated with special reagents that perceive hCG. They must be lowered into a container with urine to a certain mark and wait a few seconds. You should expect results within 5 minutes, but not later than 10;
• inkjet tests. There is no need to collect urine to perform it. It is enough to hold it under a stream of urine for a few seconds and wait for the result;
• tablet test. This option is a strip placed in a plastic tablet with two windows. A small amount of urine is placed into one of them using a pipette. The result will be visible in the next window in a few minutes;
• electronic test. It is the most accurate of all the previous ones. The principle of its operation is similar, but the result is displayed on the screen.

Accuracy check / My baby and I

Consultant: Nona Hovsepyan, consultant physician, Independent Laboratory INVITRO Text: Natalia Rubina

We, of course, understand that in a magazine like ours it’s already a little late to write about pregnancy tests. But very often visitors to the site krokha.ru have questions: “How can I tell if I’m pregnant? Can the test be wrong?

How it works?

All pregnancy tests operate on the same principle - they recognize a special hormone called human chorionic gonadotropin (hCG) in urine (tests for home use) or blood (laboratory tests). It is produced only during pregnancy. A non-pregnant woman simply cannot have it (more precisely, it can, but only in exceptional cases, which are discussed below). The amount of hCG in the body from the moment the fertilized egg attaches to the wall of the uterus doubles approximately every 2-3 days and reaches a maximum by 7 - 12 weeks of pregnancy. Its presence in the blood and urine can be detected until approximately the third week after birth.

When purchasing a pregnancy test, pay attention to its sensitivity. Typically, most tests have a sensitivity of 20-25 mIU/mL (international units per mL). They are able to recognize pregnancy only from the first day of missed menstruation. Whereas there are more sensitive (but also more expensive) tests (10 mIU/ml) that can determine pregnancy within 7-10 days from the moment of expected conception. And after a week of delay, pregnancy (if any) will be shown by any tests.

If you want to find out if you are pregnant as early and accurately as possible, it is better to go and have a blood test done at a antenatal clinic or a specialized laboratory. HCG appears in the blood faster than in the urine, so pregnancy can be determined even before the expected period (but not earlier than 7 days from the date of conception). A blood test can be qualitative (the answer will be: yes or no) and quantitative, when the analysis form will tell you the exact amount of hCG in your blood. It is better to do the second option, since then (by taking it several more times) it will be possible to monitor the dynamics of the development of pregnancy. Doing a dynamic test, in particular, is useful to recognize a pregnancy that has frozen in the early stages. If the embryo freezes in development, the hCG level stops growing, and the test will immediately show this. QUESTION ON THE SITE WWW.KROKHA.RU

Olga B. “On the second day of the delay, I took a test, and it showed two lines. But one of them is very weak. Am I pregnant? Nona Hovsepyan: Even if the second line is weak, but there, you are pregnant. However, if in doubt, re-test 3-4 days later. The level of hCG in the body will increase noticeably and the stripe will be much brighter. Can a test lie? All instructions say that pregnancy tests are 95-99% accurate. This means that there is a chance that the result will be incorrect. So, a false negative result is possible if:

• you performed the test too early and the level of hCG in the urine is still too low; ^ the test has expired (so carefully study the packaging before buying the test); • you performed the test incorrectly (although it is difficult to imagine that this is possible - everything is extremely simple there); • drinking too much liquid the day before the test can dilute the urine and reduce the concentration of hCG;

The test can also show a false positive result:

• if you are taking fertility drugs that contain hCG (usually in the form of injections); • HCG can appear in the body during hydatidiform mole, a disease associated with the pathology of the trophoblast (a temporary organ necessary for attachment of the embryo to the wall of the uterus). During hydatidiform mole, the trophoblast degenerates into a huge number of small bubbles. These bubbles occupy the entire uterine cavity and tend to grow rapidly. The main symptom of hydatidiform mole is bloody vaginal discharge due to delayed menstruation. To clarify the diagnosis, you need to see an obstetrician-gynecologist as soon as possible; • Normally, elevated hCG levels can be observed up to 3 weeks after premature birth or miscarriage. But a positive test result may also mean that remnants of the fertilized egg remain in the uterus. In order to find out, you need to do an ultrasound and, if necessary, curettage of the uterine cavity.

Cannot influence the result:

• kidney diseases; • taking contraceptive medications; • taking antibiotics; • drinking alcohol; • lactation.

What tests are there?

1. Strip tests (paper strips).

These are the simplest, cheapest and most common tests. The strip needs to be lowered for 10-20 seconds to a certain mark in a container with morning urine (it is the most concentrated). After this, place the test on a horizontal surface and evaluate the result after a few minutes. One line means you are not pregnant, two lines means you are pregnant.

2. Tablet tests.

They are designed in the same way as strip tests. Only the paper strip is placed in a plastic case. And the previously collected morning urine needs to be dropped into a special hole with the pipette included with the test. The result is also shown in the form of one or two stripes.

3. Jet tests.

Their convenience is that there is no need to collect urine anywhere—the test strip just needs to be placed under the stream. In this case, urine does not have to be morning. Inkjet tests are more sensitive. The result is assessed by one or two stripes.

4. Electronic tests.

They have a special strip - a sample receiver, which you can optionally lower into a container with urine or place under the stream. The result is read in 3 minutes. If “+” or the inscription “pregnant” appears on the test, you are pregnant, but if “-” or “not pregnant”, you are not.

5. Interactive tests.

Recently, a lot of so-called virtual or interactive tests have proliferated on the Internet. But there is not the slightest sense in believing them. At best, this is just a scam, at worst, it’s a way for scammers to make money. So, in the simplest tests, you are asked to place your finger on a square on the screen, and if after 2 minutes it turns red, you are pregnant, but if the square turns blue, you are not. The square turns red even if you don't touch the screen. Apparently this test is for those who have no doubt that they will soon become a mother. More complex tests ask you to answer a number of questions, including “Have you recently had unprotected sex?” and “Do you feel engorgement in your breasts?” As a result, it is proposed to receive a response after sending an SMS to a specific number.

Can a test detect an ectopic pregnancy?

If the fertilized egg has implanted outside the uterus, a regular pregnancy test will still be positive. However, such a pregnancy, as a rule, is terminated at 7-8 weeks, and this is accompanied by large blood loss and serious problems for the woman’s health. To avoid this, it is better to recognize and terminate an ectopic pregnancy in advance (it is impossible to save it).

The main symptoms of an ectopic pregnancy: with a positive pregnancy test, nagging pain in the lower abdomen and spotting appear. In this case, you need to get an ultrasound as soon as possible. With an ectopic pregnancy, there is no fertilized egg in the uterine cavity, but the doctor will notice the growth of the endometrium, as in a normal pregnancy.

If you belong to a risk group (adhesions, inflammation of the appendages, or have previously had an ectopic pregnancy), then it is better to conduct a high-quality pregnancy test using blood over time. During an ectopic pregnancy, the level of hCG in the blood is lower than during a normal pregnancy, and the test will immediately show this.

IT IS IMPORTANT!

Despite the fact that all women have different lengths of the menstrual cycle, the period after ovulation for all is 14 days, which means that by the beginning of the next cycle, pregnancy can already be determined, since implantation of the fertilized egg occurs approximately 6-7 days after conception.

FOLK WISDOM

When there were no pregnancy tests yet, our ancestors knew other ways to diagnose pregnancy.

Collect some urine in a jar and drop a drop of iodine into it. If the drop dissolves in urine, this indicates the absence of pregnancy. If the drop holds a large shape, the woman is pregnant.

In Ancient Greece, it was believed that a pregnant woman's iris became slightly darker.

Water the flowers in the flower bed with morning urine. If the flowers bloom very profusely after this, it means the woman is pregnant.

Take two onions and plant them in two pots. Write “yes” on one and “no” on the other. Water both bulbs with morning urine and wait until one of the sprouts sprouts. If the bow with the inscription “yes” is the first to “throw out an arrow,” this means that pregnancy has occurred.

Is it difficult to take a pregnancy test at home?

Carrying out the test at home does not present any difficulties. It can be purchased at any pharmacy without a prescription or in a supermarket. In addition to their accessibility, the tests are highly accurate. The main task when performing them is to strictly adhere to the instructions. The correct result should be expected after the time interval indicated in the instructions. A result that appears earlier or later than the specified time is not correct. If a woman has doubts about the reliability of the result, it is better to contact a gynecologist.

If the test is negative and you are pregnant

The test is false negative if the urine collected for the test is too dilute. An interesting fact is that

If you drink 2-3 glasses of water in the evening, visit the toilet a couple of times at night, and take a test in the morning, the result is false.

To make the result accurate:

• take a pregnancy test in the morning, immediately after waking up
• do not forget to wash yourself before collecting urine
• don't rush to take the test

The urine that accumulates in the body overnight has a high concentration of the hormone hCG, which is responsible for a positive test result, so the test recommendation is to perform the test immediately after waking up. Be sure to follow hygiene procedures - wash yourself before collecting urine. Since vaginal mucus or any other discharge may affect the result.

Taking a pregnancy test too quickly can lead to a false result. You must wait before performing it.

How accurate are pregnancy tests?

Home tests do not provide a complete guarantee of obtaining a reliable result; mistakes sometimes occur. To achieve more accurate data and minimize possible errors, the following rules must be followed:

• It is advisable to carry out pregnancy tests in the morning, since the largest amount of the hormone is concentrated in the urine overnight;
• Before conducting a urine test, the test should not be exposed to dirt or moisture;
• It is unacceptable to use the test after the expiration date;
• foreign substances should not penetrate into the urine sample;
• the test kit should be stored at a temperature of 2 to 28C;
• When performing the test, you must strictly follow the instructions.

Reasons for the error

If you suspect pregnancy, regardless of whether the test is positive or not, you should check with your doctor to get a reliable answer.

There are many reasons why a pregnancy test may have a false result:

• low-quality cheap tests;
• expired expiration date;
• violation of packaging tightness;
• failure to follow instructions when conducting the test;
• foreign substances entering the urine sample;
• the pregnancy period is insufficient for the test;
• pathological pregnancy;
• there is a high probability of miscarriage;
• the presence of diseases that change hormonal levels;
• taking certain medications that affect hormone production;

• Excessive fluid intake before performing the test.

Blood test for hCG

In addition to home tests, doctors recommend taking a blood test. It is more informative, since the concentration of the hormone in the blood is several times higher than in the urine. The test can detect pregnancy earlier than urine tests, but it takes longer to complete.

There are 2 main types of blood tests for hCG:

• qualitative. Answers the question: is the hormone level elevated or not, which indirectly suggests the presence or absence of pregnancy in a woman;
• quantitative (beta-hCG). This analysis reflects the exact concentration of the substance in the blood, so the doctor can monitor hormonal changes over time.

To obtain correct blood test results, you must adhere to the following rules:

• the analysis is performed strictly on an empty stomach in the morning;
• 12 hours before the test, alcohol consumption, physical activity, and smoking should be completely avoided;
• In the morning on the day of analysis, drinking water is allowed;
• It is necessary to avoid taking any medications. If this is not possible, you need to notify the laboratory and doctor.

Determining pregnancy is not the only task of a blood test for hCG. As noted earlier, during the formation and development of the embryo, the level of the hormone in a woman’s body should gradually increase - up to the 12-13th week of pregnancy. If, with regular observation, an increase in hCG is not observed or the hormone level does not correspond to generally accepted standard values ​​for a specific period, then this may indicate the development of a frozen or ectopic pregnancy, with a high probability of miscarriage.

At later stages, quantitative determination of hCG can be used as a screening for genetic disorders in the fetus (Down or Edwards syndrome). The determination of beta-hCG also plays an important role. If a woman’s level of this hormone is elevated, but other characteristic signs of pregnancy are not observed, tumor diseases should be suspected.

Reasons for missed periods with a negative test

The situation can arise for various reasons. They depend on the woman’s health condition and the true duration of the delay. It is important to understand exactly when your last menstruation was. In any case, a delay in your period is not a reason to panic: it is not always pregnancy or illness.

Let's look at the delay times in more detail.

Delay in menstruation by one day

• Failure of menstruation.
  This is possible due to climate change and accumulated fatigue. The cycle also shifts when taking certain medications, in particular antibiotics. A one day delay is no big deal. Conclusion: you don’t need to do anything on the first day of the delay.
• You are pregnant, but the test was taken early
  . The instructions for the tests say that pregnancy can be tested almost from the first day of the delay. Gynecologists say that this is not so. It happens that the hCG level is low and the test will not detect it even after a week. Sometimes a woman does not know when and on what day conception occurred, so she incorrectly calculates the period.
• Menstrual flow is delayed by a polyp
  . Blockage of the cervix by a polyp leads to atresia, which restricts the flow of menstrual blood. Then, even if your period has begun, the blood will remain inside the uterus for some time. This pathology is called hemotometer. When the uterus fills with blood, it swells, the blood inside stagnates and deteriorates. This condition is a direct threat to life.

If during the menstrual cycle, when your period should come, there is no discharge, but your lower back, lower abdomen hurts, you feel nauseous, and your temperature is elevated, you need to urgently make an appointment with a gynecologist.

Delayed menstruation by seven days

Is this condition dangerous and does it always indicate pregnancy? No! The egg may be delayed from leaving the ovary, which is why menstruation is delayed by a week, even if the woman is not pregnant! You need to wait 3-4 days and take a blood test for hCG. Tests will definitely show whether there is a pregnancy. If you do the tests twice, you can take an online hCG test

Ten days delay in menstruation

If the test gives a negative result, but there is still no period, you need to think: most likely there is a pregnancy, but with a negative test, we can say that it is developing incorrectly or has stopped altogether, and therefore the level of gonadotropin is lower than usual. After a week, if menstruation does not begin, you need to see a gynecologist, get tested for hCG and undergo an ultrasound of the uterus.

Delay in menstruation by 15 days

If there is no delay in menstruation on the 15th day, this is a serious cause for concern. In theory, a new ovulation should occur at this time.

The reason for long delays is not always a normal pregnancy:

• Anemia . A low level of hemoglobin leads to the fact that the female body begins to “save” blood, blocking menstruation.
• Body weight is significantly below normal
  . By losing 10-15 kg in a month, you can achieve amenorrhea.
• Inflammation of the ovaries
  . When inflammation occurs, the release of the egg is disrupted. The production of hormones is disrupted, which causes amenorrhea.
• Diseases of the uterus
  . This category includes endometritis, organ atrophy, and endometrial hypoplasia. With these pathologies, the functional layer of the endometrium becomes thinner and does not exfoliate during menstruation. Accordingly, there is no bleeding. With inflammation, the temperature rises, the lower back and stomach in the area of ​​the uterus hurt.
• Pituitary tumor
  . The reason is hormonal changes in the body, leading to a temporary cessation of menstruation - amenorrhea. The tumor disrupts the functioning of the thyroid gland and adrenal glands - it is in these organs that hormones are produced.
• Placental insufficiency
  . Since the embryo does not receive enough nutrients, the pregnancy does not develop well.
• Polycystic ovary syndrome
  . With this disease, cysts form in the ovary. As a result, the secretion of estrogen is disrupted, and the woman’s menstrual cycle is disrupted. Menstrual function may be restored, but then goes astray again.
• Serious illnesses and infections
  . A weakened body may not menstruate in the next menstrual cycle

Psychological reasons

• False pregnancy.
  In this case, menstruation with a negative test is a pattern. With a false pregnancy, the signs of pregnancy are caused by self-hypnosis. This happens if a woman is afraid of getting pregnant or, on the contrary, really wants to have children.
• Stress
  . In a depressed mood, the production of necessary hormones by the hypothalamic-pituitary system is blocked.

Causes of prolonged delay of critical days associated with abnormal pregnancy

• Anembryonic pregnancy
  . An embryo does not develop inside the fertilized egg.
• Ectopic pregnancy
  . With this pathology, the fetus is fixed and develops not in the uterus, but in other reproductive organs: the ovary, cervix, oviduct, peritoneum.
• Frozen pregnancy . There was a fruit, but it died.

If a repeat pregnancy test is negative and menstruation does not occur, you need to see a doctor, undergo an ultrasound and a full examination.