Ovulation is ejection of an immature egg (oocyte) from the ovary. Ovulation occurs midway through the cycle, around the 14th day. When estrogen levels reach a peak, the anterior pituitary gland releases LH. The LH surge triggers ovulation at the midpoint of the ovarian cycle.
Following ovulation, the follicle cells remain dormant and the corpus luteum cells begin to function. Corpus luteum formed during ovulation survives for exactly 14 days.