If your period is delayed again, if you had sex during this period without good contraception, you should first rule out an unwanted pregnancy. Usually more than 12 days after intercourse you can use a test paper or come to the hospital for a blood test for HCG to rule out the possibility of pregnancy. If pregnancy is completely ruled out, ultrasound examination can be done. If the uterine adnexa are normal and the thickness of the endometrium is moderate, progesterone can be taken or progesterone injection can be given to promote the onset of menstruation. If you take progesterone, it is usually 200mg/day for 5 days, and you can stop taking it during your menstruation. It is generally recommended to take blood test for endocrinology on the 3rd day of menstruation to see if there is polycystic ovary syndrome, and if there is, it is recommended to use Da-Ying-35 to regulate menstruation, which is generally taken on the 5th day of menstruation, 1 tablet/day for 21 days, stop taking it after 21 days to wait for menstruation, and so on.