Take progesterone for three days and still have not come to menstruation, we should pay special attention, generally after taking progesterone within 3-5 days will come to menstruation, pay attention to dietary habits during the medication, do not eat spicy and stimulating food, pay attention to rest, strengthen diet and nutrition, regular re-examination. If you have sexual intercourse without contraception, you may also be pregnant. You can take an early pregnancy test, draw blood to check HCG in the blood and use early pregnancy test paper to check whether you are pregnant. If pregnancy is confirmed, do not use medicine at will, so as not to affect the development of the baby. Pay attention to eating more vegetables and fruits, which can be supplemented with vitamins to prevent the symptoms of early pregnancy reaction during pregnancy, and ultrasound should be performed regularly to observe the development of the baby. You should take folic acid supplement, 4mg/d.