FSH, LH, Estrogen, Progesterone are 4 main players in regulating the menstrual cycle. Two of them are from the pituitary glands (Gonadotropins) and the other two are from the ovaries (Ovarian or sex hormones). FSH (Follicle Stimulating hormone) to mature the follicles. LH (Luteinizing hormone) that causes the ovulation. Estrogen that controls the LH surge