Here are some more reasons why intercourse is an excellent way to relieve stress. The act of copulation or medically referred to as coitus is rather popularly known to most people as sexual intercourse. A progesterone blood test is performed to discover how much of the progesterone hormone is in a sample of blood. This female hormone is produced whenever a mature egg is released from an ovary after a process generally known as ovulation. This hormone helps you to prepare the endometrium (uterine lining) to just accept the egg if sperm fertilizes it. If the egg goes without having to be fertilized, menstrual bleeding occurs and progesterone levels drop.