Menstruation time is long, the doctor gave me progesterone, what role does progesterone have?

Progesterone is a natural progestin secreted by corpus luteum of ovary, which has significant morphological effect on endometrium stimulated by estrogen in vivo and is necessary to maintain pregnancy. Its pharmacological effects are as follows:

① In the late menstrual cycle, the glands in the uterine mucosa grow, the uterus is congested, and the endometrium thickens to prepare for the implantation of fertilized eggs. After implantation, the fertilized egg will produce placenta, which will reduce the excitability of pregnant uterus, inhibit its activity and make the fetus grow safely.

(2) Under the same effect as estrogen * * *, promote the full development of breasts and prepare for milk production.

③ The cervix is closed, mucus is reduced and thickened, and sperm is difficult to penetrate; At high dose, hypothalamic negative feedback inhibits the secretion of pituitary gonadotropin, leading to ovulation inhibition.