3. Reproductive cycle Devided into 3 phases O Menstruation: 1-4days O the follicular phase: 5-14 days a number of follicles developing, only one dominant follicle others become atretic ovulation: 14th. releasing oocvte luteal phase: 15-28 days unless pregnancy occurs3.Reproductive cycle Devided into 3 phases ❑Menstruation: 1-4days ❑ the follicular phase:5-14 days a number of follicles developing, only one dominant follicle others become atretic ovulation:14th, releasing oocyte ❑ luteal phase: 15-28 days unless pregnancy occurs