How Ovulation Happens

Once the egg has been released, the cells of the follicle remaining in the ovary quickly change and become known as the corpus luteum. These cells then begin to produce significant amounts of progesterone in addition to estradiol. Progesterone induces the cells of the lining of the uterus to undergo the changes that will allow an embryo to implant and begin to grow.

The life span of the corpus luteum is limited. Unless a pregnancy occurs and continues to stimulate it, the corpus luteum will produce progesterone for only 12 to 14 days. As the corpus luteum begins to fail and progesterone production falls low enough, the cells of the lining of the uterus will begin to shed, a menstrual period begins, and the whole process starts over.

The life span of the corpus luteum is limited. Unless a pregnancy occurs and continues to stimulate it, the corpus luteum will produce progesterone for only 12 to 14 days. As the corpus luteum begins to fail and progesterone production falls low enough, the cells of the lining of the uterus will begin to shed, a menstrual period begins, and the whole process starts over.

Of course, not all menstrual cycles are exactly 28 days long. Cycles from 26 to 30 days or even longer may be normal. Normal ovulation occurs 14 days before the onset of the next menstrual period. Therefore, in a 32-day cycle, ovulation probably occurs on or about day 18.

If a woman has regular menstrual cycles, she is in all probability ovulating. However, there are instances in which bleeding can occur in the absence of ovulation, but this bleeding is typically very irregular and often abnormal in amount or duration.