Ovulatory phase/Pre-luteal/Post-follicular: During this phase, ovulation takes place. It usually occurs on the 14th day of the cycle of 28 days menstrual cycle. The mature Graafian follicle ruptures due to LH secreted by the pituitary. Due to LH surge, the Graafian follicle ruptures and releases the secondary oocyte in the abdominal cavity.