The period has been early and suddenly postponed. For this case, first of all, we need to exclude the delay of menstruation caused by pregnancy. If the patient has fertility requirements, further gynecological ultrasound, blood HCG and progesterone are needed to determine if the pregnancy should be settled or treated with progesterone supplementation based on the test results. If the patient does not have fertility requirements, blood tests for HCG and gynecological ultrasound are also needed. If the gynecological ultrasound indicates early intrauterine pregnancy, the pregnancy needs to be terminated as soon as possible; if the blood HCG value indicates no pregnancy, in this case, further dydrogesterone 10 mg twice a day for 10 days, stopping the medication and waiting for menstruation, most of them will have menstruation within two weeks of stopping the medication.