Pregnancy tests are designed to detect the pregnancy hormone Human Chorionic Gonadotropin (hCG). This hormone increases when a fertilized egg implants in the woman's uterus. Therefore, an elevated level of hCG in the woman's urine indicates pregnancy. Pregnancy tests have two antibody lines. One is the control line, which turns color when dipped in urine. If the control line appears with color, it confirms that the test is functioning properly. The other line is called the test line, and this line only turns color if your urine contains the amount of hCG that is sensitive to your pregnancy test. See an example of a positive Femometer Pregnancy Test Strip in the product images.
Pregnancy tests are of such high quality today that they are more than 99% reliable and accurate from the expected day of menstruation. However, it is possible to be pregnant even if your pregnancy test is negative. This is especially true if you test before the expected day of menstruation.
The reliability of early and common pregnancy tests today is so high that it is extremely rare to have a false positive result. If your test is positive, meaning a colored line appears on the pregnancy test's test line within the specified time frame, then you are pregnant.
However, some individuals may still experience menstrual bleeding on their expected period day or a few days later, leading them to think that the pregnancy test was a false positive. In most cases, this is due to a biochemical pregnancy loss, which is an early miscarriage occurring around weeks 3-5. During this period, pregnancy can only be detected through a pregnancy test or a blood test, as a fetal heartbeat cannot be seen on an ultrasound scan. Nevertheless, if a colored line appears within the specified time frame as stated in the instructions, it indicates an elevated hCG level, which means that you are or were pregnant.
Note that there are medications, such as Ovitrelle, that can cause an increase in hCG levels without being pregnant.
hCG begins to rise when the fertilized egg implants itself 5-10 days after fertilization by a sperm cell and starts dividing. The level of the pregnancy hormone hCG then rises rapidly and doubles every three days in the first 12 weeks of pregnancy.
Clinical tests have shown that 99% of all pregnant women can test positive on a standard pregnancy test on the day of expected menstruation
Yes, it is possible to be pregnant even if the pregnancy test is negative. This is especially true if you test before the expected day of menstruation.
There can be a significant variation in the time it takes for a fertilized egg to reach the uterine cavity. It can range from one day to one week, which is considered normal. Since the production of the pregnancy hormone hCG starts when the egg implants in the uterus, some individuals may have a positive pregnancy test one week before the expected menstruation, while others may have a positive test a few days after the expected menstruation day.