Anovulatory cycle In other cases, menstruation may be fairly regular (eumenorrhea), or more frequent (intervals < 21 days), or there may be a loss of menstrual pattern (menorrhagia, dysfunctional uterine bleeding). Normal menstrual bleeding in the ovulatory cycle is a result of a decline in progesterone due to the demise of the corpus luteum. It is thus a progesterone withdrawal bleeding. As there is no progesterone in the anovulatory cycle, bleeding is caused by the inability of estrogen — that needs to be present to stimulate the endometrium in the first place — to support a growing endometrium. Anovulatory bleeding is hence
Menstrual cycle continue to secrete progesterone to maintain the new pregnancy. Most pregnancy tests look for the presence of hCG. The uterine cycle has three phases: menses, proliferative, secretory. Menstruation (also called menstrual bleeding, menses, catamenia or a period) is the first phase of the uterine cycle. The flow of menses normally serves as a sign that a woman has not become pregnant. (However, this cannot be taken as certainty, as a number of factors can cause bleeding during pregnancy; some factors are specific to early pregnancy, and some can cause heavy flow.) "Eumenorrhea" denotes normal, regular menstruation that lasts for a