The absence of menstruation requires further management depending on the cause. First, pregnancy-related conditions, such as pregnancy or ectopic pregnancy, need to be ruled out. Second, an ultrasound of the uterus and both adnexa is needed to see the thickness of the endometrium. If the endometrium is very thick, menstrual irregularities are considered. At this time, you need to regulate menstruation. You can take progesterone capsule 0.1g orally twice a day for 6 days, and you will usually stop taking the medicine for 3-5 days to get your period. You can use progesterone injection, 20mg intramuscularly each time, for 3 days, also 3-5 days after stopping the medication will come to menstruation. You have to go for ultrasound of both uterine attachments to see if there are any uterine adhesions. If there are uterine adhesions, you need to do hysteroscopic separation of uterine adhesions and intrauterine device placement after surgery to avoid recurrence.