The vast majority of women’s menstruation is 3-7 days clean, if the past menstruation is clean within the normal time, suddenly a period 2 days clean, pay attention to exclude the following causes caused by: 1, if there is a normal sexual life, did not take contraceptive measures, this situation to exclude the possibility of pregnancy, some women are pregnant, in the usual time of menstruation, there will be a small amount of vaginal bleeding, it is recommended 2, caused by a disease, such as polycystic ovary syndrome, premature ovarian failure, may lead to reduced menstrual flow, it is recommended that blood tests for sex hormone six can be taken to give a preliminary diagnosis.