UTERINE PHASES OF MENSTRUAL CYCLE

SECRETORY PHASE

Technically, this phase begins at ovulation and includes the earlier phase. Under normal circumstances it is consistently 14 days in duration. Secretory phase does not occur if ovulation has not occurred.

If pregnancy does not occur in that cycle, oestrogen and progesterone secretion declines. This causes a series of rapid regressive changes in the endometrium on the 13^th, 14^th days after the ovulation (27^th-28^th day of cycle), leading to menstruation within a few days. The glands expel their secretion, thus decreasing the thickness of the endometrium.