Usually, the gestational sac can be seen in the uterine cavity on the 35th day of menopause, but if the gestational sac is not seen and bleeding is present, it is necessary to consider whether biochemical, pre-eclampsia or ectopic pregnancy has occurred. 1. Biochemical pregnancy: the sperm-egg union has not settled, or it is discharged with the menstrual flow after settling. Generally, no special treatment is needed, daily attention should be paid to keep the vulva clean, reduce bacterial infection, enhance warmth and avoid getting cold as much as possible; 2. Pre-eclampsia: the absence of the gestational sac on ultrasound may be caused by the small development of the gestational sac which is not easy to observe, at this time, if the bleeding is small, often dark red or bloody leucorrhea, may be accompanied by mild lower abdominal pain or back pain, go to the hospital blood test results can be seen in the blood human chorionic gonadotropin If the blood test results show a doubling of chorionic gonadotropin in the blood, consider the possibility of preterm abortion. 3. Ectopic pregnancy: If the fertilized egg is laid outside the uterine cavity, it may show abdominal pain and vaginal bleeding, and the gestational sac cannot be seen in the uterine cavity on ultrasound. Since ectopic pregnancy may cause intra-abdominal hemorrhage or even hemorrhagic shock and death of the pregnant woman, a comprehensive examination and timely treatment must be actively carried out, and surgical treatment should be performed if necessary.