Definition
A pregnancy test determines if a woman is pregnant. It detects the presence of human chorionic gonadotropin (hCG) in urine or blood. hCG is a hormone produced during pregnancy. Home tests are urine-based, while blood tests are done in a doctor's office. A positive result indicates pregnancy; a negative result may mean no pregnancy, or it's too early to detect. Think of it as a chemical detective solving a biological mystery. It is easier and quicker than waiting for a stork.