… Continued …
Whether or not conception happens – your body will produce progesterone for about 14 days after the egg released from ovary (ovulation).
The production of progesterone after ovulation is mainly functioned to help a fertilized egg /embryo to implant in the thickened lining of uterus (endometrium) that has been prepared in the first half of your menstrual cycle !
Progesterone is secreted by corpus luteum (a structure that is derived from the ruptured follicle where the matured egg comes from, as noted before). This hormone and with small amounts of oestrogen are also required to maintain endometrium, waiting for a fertilized egg to implant.
If fertilization occurs and an embryo has implanted on the endometrium, your body then will activate other essential hormones to support the pregnancy. One of them is the production of hormone called HCG (human chorionic gonadotrophin).
Many home pregnancy-tests detect the existence of HCG in the urine to conclude whether or not you get a pregnancy.
HCG can play a key role to help maintain the corpus luteum. And then corpus luteum is needed to help the female body keeps producing progesterone for maintaining the endometrium.
If there is no embryo (fertilized egg) that implants in the endometrium, your body will not produce essential hormones to support pregnancy, and the corpus luteum will go away to prepare the new egg for ovulation in the next menstrual cycle.
As a result, the production of progesterone discontinues. Right before your menstrual bleeding starts, the uterus secrets prostaglandins to stimulate the muscles of uterus lining to get contraction and shed the endometrium, and you notice your menstrual flow.
All of these sites accessed on Jan 2014