The absence of menstruation can be caused by pregnancy, and there are many other reasons for the absence of menstruation. It may be caused by abnormal ovarian function or hypothalamic-pituitary-ovarian axis, as well as uterine abnormalities that lead to the lack of menstruation. It is necessary to perform sex hormone six tests and ultrasound to understand the thickness of the uterine endometrium, and if necessary, to perform estrogen and progesterone tests to further find out whether there are corresponding uterine adhesions that lead to the lack of menstruation, and then to give the corresponding treatments after finding out the specific causes. Therefore, there is a possibility of pregnancy, but there are also some other reasons for not having a menstrual period.