Pregnancy tests: when is it better to take the pregnancy test?
Many of the women who are seeking to conceive doubt when the time is right to take the pregnancy test. Some believe that it is necessary to wait until the first day of the absence, while others wonder if they can do it before.
Currently, it is already possible to do test or pregnancy test from the moment of implantation, that is, between three and 12 days after ovulating. However, it is much better to wait until the first day of the absence to know if you have become pregnant because getting tested before carries a higher risk of false positives and negatives.
The pregnancy hormone
The reason is that it is necessary to give time to have a sufficient level of hCG, a hormone present in pregnancy essential to detect it with tests and pregnancy tests. The concentration of Human Chorionic Gonadotropin (hCG) is a hormone that is released during pregnancy and that is produced by the embryo. This concentration varies from one woman to another, although they are in the same phase of pregnancy. For this reason, there are cases in which the detectable levels are not reached until the first day in which the rule is supposed to arrive.
It should be remembered that a high percentage of pregnancies end in natural or spontaneous abortion very soon, even before the period has to come. Despite this, hCG can continue to exceed the detectable threshold for days, resulting in a false positive.
How to avoid a false positive pregnancy test
To prevent the pregnancy test from giving a false positive, it is recommended:
1. Take the test on the day the rule has to come, not before.
2. Repeat the test two days later, regardless of the result. If the second test is positive, but the first test was negative, the hCG levels may not have increased enough to be detected. In case the first test comes out positive and the second negative, there would have been a very early pregnancy loss, an episode known as chemical pregnancy.
Factors that can cause a false positive in the pregnancy test
1. The peak of HL. Sometimes, the pituitary gland can release hCG at the peak of HL (luteinizing hormone). If the timing of the test matches that peak, there is a small chance that a false positive will come out.
2. Chemical pregnancy. A high percentage of early pregnancies are aborted even before the rule comes down. If the test is done too soon, it may detect a non-viable early pregnancy.
3. Perimenopause. Women in the perimenopausal period have somewhat elevated levels of hCG in circulation, even if they are not pregnant. This can result in a false positive.
4. Fertility treatment. Women who are on hCG treatment to stimulate ovulation may receive false positives if they are tested within 10 days after their last injection.
Factors that can cause a false negative in the pregnancy test
1. Take the test too soon. In the early stages of pregnancy, not all women produce enough hCG for the test to detect.
2. Use a test that is not sensitive enough. If the test is done soon, it is advisable to use a more sensitive test.
3. Diluted urine. Drinking a large amount of liquid shortly before the test can cause the hCG to be too diluted to be noticed.
4. Do not use urine immediately. If it takes a long time since the urine sample is taken before the test (usually about 30 minutes), it may result in a false negative.
What type of pregnancy test is the best?
Most market tests are reliable and give positive results in 98 percent of pregnant women. In spite of this, doing the test too early may result in unsuccessful results.
The more sensitive the pregnancy test is, the more likely it is to detect early pregnancy. However, pregnancy tests of this type are also more likely to give false positives.
Blanca Prieto
It may interest you:
- First trimester of pregnancy
- Get pregnant: odds according to your age
- Pregnancy symptoms
- Fertile day calculator
Pregnancy calendar week to week
Click on each petal or circle to see the content of your week or trimester of pregnancy respectively.
