You can also be tested by a Maternity Doctor in gurgaon . All pregnancy tests operate by identifying a unique hormone in a woman's urine or blood that only appears when she is pregnant. It's known as hCG (kohr-ee-ON-ihk goh-NAD-uh-TROH-puhn) or human chorionic gonadotropin (kohr-ee-ON-ihk goh-NAD-uh-TROH-puhn). When a fertilised egg implants in the uterus, HCG is produced.