A pregnancy test, also known as a Rapid Diagnostic Test (RDT), is a simple and reliable way to detect the presence of the hormone human chorionic gonadotropin (hCG) in a woman's urine. hCG is produced by the placenta after a fertilized egg implants in the uterus. The test usually involves collecting a small sample of urine in a cup and then using a dropper or stick to add a few drops of the urine onto a special strip or card. The strip or card contains chemicals that react with hCG if it is present in the urine. Depending on the type of test, you may need to wait a few minutes for the results to appear. If the test is positive, meaning hCG is detected, it usually means that the woman is pregnant. If the test is negative, meaning no hCG is detected, it usually means that the woman is not pregnant. However, it's important to note that false negative results can occur if the test is taken too early in the pregnancy or if the urine is too diluted.