Women in the luteal phase will have a continuous secretion of estrogen and progesterone, under the stimulation of estrogen and progesterone, the endometrium is secretory response, so there will be no vaginal bleeding, menstruation performance. If there is brown discharge during the luteal phase, and there is no stimulation caused by coitus, it is necessary to consider that it may be due to luteal insufficiency or luteal atrophy, resulting in abnormal bleeding, the menstrual period will be significantly prolonged, and there may be a shortening of the menstrual cycle phenomenon, you need to check the hormone six items to determine. For women who have had a cesarean section to terminate their pregnancy, if there is brown discharge in the luteal phase after the return of menstruation, it is considered that it may be caused by uterine scar incision diverticulum, and if there is brown discharge after coitus, even in the luteal phase, it is considered that it may be caused by cervical polyps or cervical erosion.