|How do pregnancy tests work?
Pregnancy tests look for a special hormone (hCG) in the
urine or blood that is only present when a woman is pregnant.
After the fertilized egg is implanted in the uterus, the
placenta begins to develope and excretes hCG. The test will
bind the hormone from the urine or blood to an antibody,
which finally, in connection with an indicator, displays
the result on a display.
Pregnancy tests - Accuracy
Pregnancy tests - Factors
Pregnancy tests - Types