Human chorionic gonadotropin (hCG) is a hormone produced during pregnancy in the cells of the placenta. The presence of hCG triggers at-home pregnancy tests to turn positive. The amount of hCG in a ...

Here’s why: Doctors measure pregnancy on a calendar that lasts 40 weeks and starts on day one of the cycle in which you became pregnant. So, your first official day of pregnancy is the first day of ...