Pregnancy tests are designed to detect the pregnancy hormone Human Chorionic Gonadotropin (hCG). This hormone increases if a fertilized egg implants in a woman's uterus. Therefore, an elevated level of hCG in a 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 indicates that the test is functioning correctly. The second line is called the test line, and this line only turns color if your urine contains the amount of hCG that your pregnancy test is sensitive to.
See an example of a positive Gravidtid Pregnancy Test Strip in the product images.
Pregnancy tests today are of such high quality that they are more than 99% reliable and accurate from the day of expected menstruation. However, it is still possible to be pregnant even if your pregnancy test is negative. This is especially true if you test before your expected period.
The reliability of early and standard pregnancy tests today is so high that it is extremely rare for a false positive to occur. If your test is positive - meaning if a colored line appears on the test line of the pregnancy test within the specified time frame - then you are pregnant.
However, some individuals may still experience menstruation on the expected date or a few days later, leading them to believe that the pregnancy test was a false positive. In most cases, this is due to a biochemical pregnancy loss, which occurs in weeks 3-5 of pregnancy. During this period, a pregnancy can only be detected through a pregnancy test or a blood test, and a fetal heartbeat would not be visible on an ultrasound. Nevertheless, if a colored line appears within the specified time frame stated in the instructions, it indicates an elevated hCG level, meaning that you are or were pregnant.
Please note that there are medications, such as Ovitrelle, that can cause an increase in hCG levels without pregnancy.
hCG starts to rise when the fertilized egg has implanted itself 5-10 days after fertilization by a sperm cell and has begun to divide. The level of the pregnancy hormone hCG then increases rapidly and doubles every three days during the first 12 weeks of pregnancy.
Yes, it is possible to be pregnant even if the pregnancy test is negative. This is especially true if testing is done before the expected day of menstruation.
There can be a significant variation in the time it takes for a fertilized egg to reach the uterus. It can range from one day to one week, and during this time, the production of the pregnancy hormone hCG has not yet started. The hCG hormone is produced when the fertilized egg implants in the uterus. As a result, some individuals may have a positive pregnancy test a week before the expected menstruation, while others may have a positive test a few days after the expected menstruation.