How do Pregnancy Tests work?

All pregnancy tests work by detecting a certain hormone in the urine or blood that is only there when a woman is pregnant. This hormone is called Human Chorionic Gonadotropin (HCG). It is also called the pregnancy hormone. hCG is made when a fertilized egg implants in the uterus. This usually happens about six days after the egg and sperm merge. But studies show that in up to 10 percent of women, implantation does not occur until much later, after the first day of the missed period. The amount of hCG rapidly builds up in your body with each passing day you are pregnant. 

SurePredict tests work by testing for Human Chorionic Gonadotropin (HCG).  HCG is a hormone produced by a trophoblastic tissue and it appears around the 8th to 9th day after ovulation.  In a 28 day cycle with ovulation occurring at day 14, HCG can be detected in urine or serum in minute quantities around day 23, or 5 days before the expected menstruation. The hormone concentration doubles approximately every 2 days and peaks 7-12 weeks after first day of the last menstrual period.  IN normal subjects, HCG is urine provides an early indication of pregnancy.  The elevated HCG levels are also associated with trophblastic diseases and certain nontrophoblastic neoplasms.  This, the possibility of other diseases must be eliminated before the diagnosis of pregnancy can be made.  

The detection limit for the HCG test kits is 10 mIU/ml HCG.  Urine samples equal to or greater than 10 mIU/ml will be tested positive.  Samples containing less than 10 mIU/ml HCG may also produce a very faint positive line.  

You can read and download the instructions that come with our SurePredict pregnancy and ovulation tests here on our website.

This definition was provided from Women's Health.com