Normal Menstrual Cycle

Normal menstrual Cycle progresses as follows

1)Follicular Phase(1-13 days)
2)Ovulation(14th day)
3)Luteal phase(days 15-28)

Follicular Phase (1-13 days)(Proliferative phase):
Variable phase, lasts around 13-14 days. In the beginning of follicular phase after the 5th day of menses there is increase in FSH level which lead to growth of ovarian follicles which in turn increases estrogen production. This results in development of straight glands and thin secretions of the uterine lining.

Ovulation(14th day):
Just before ovulation estrogen level reaches its peak, followed by spike in LH and FSH leading to rupture of follicle and release of mature ovum. Ruptured follicular cells involutes and form the corpus luteum.

Luteal phase(15-28):
Duration is fixed(14 days), during this phase there is increase in progesterone levels, its called the secretory phase, the corpus luteum produces estrogen and progesterone allowing the endometrial lining to produce thick branching endometrial glands with thick secretions.
The corpus luteum can survive for 14 days without further LH stimulation, if fertilization doesn't occur the corpus luteum cannot be sustained and endometrial lining sloughs of at 28 th day of the cycle.