Certain organic chemicals called hormones are necessary for the body to carry on its functions. Progesterone is one of the hormones that regulates the reproductive processes of the female. It circulates in the blood stream.
   Progesterone is produced by the corpus luteum, a tissue of the ovary which develops after ovulation. Under the influence of progesterone, the lining of the uterus becomes highly developed and prepared to receive a fertilized egg. The continuous production of progesterone during pregnancy keeps the uterus in the proper condition for the development of the fetus or child.