The ovarian cycle is a monthly series of events in the ovaries that can be divided into the follicular phase and the luteal phase, with both being 14 days long (or 28 days in total)

The ovarian cycle has to be initiated (switched on) and suppressed (switched off) in a precisely regulated sequence every month.

The Ovarian Cycle - http://en.wikipedia.org/wiki/Menstrual_cycle

1), 2), 3) The follicular phase (days 1-14) : the ovarian follicles mature and get ready to release an egg. Usually by day 14, only one follicle has become fully mature, and the ovum it contains is ready to be released. 4) Ovulation: the ovum travels down the fallopian tube and into the uterus.

5) The luteal phase (days 15-28) : development of the corpus luteum. The uterus is prepared 'just in case' of pregnancy and the lining of the uterus (endometrium) is thickened. The corpus luteum begins to secrete progesterone, and a small amount of oestrogen.

6) If fertilisation does not occur after ovulation: the corpus luteum will degenerate, production of progesterone will decrease and the outermost layer of the endometrium begins to break down and leaves the body during menstruation. After menstruation, the ovaries start to make more oestrogen again, and another lining begins to grow.