The gestational sac can be observed by transvaginal ultrasound around 35 days after early pregnancy, and the intrauterine gestational sac can be observed by transabdominal ultrasound after 42 days after conception. After 42 days, transabdominal ultrasound can also observe the location of the gestational sac, its size and shape, as well as the size and shape of the yolk sac, and the condition of the fetal buds and the fetal heart. Generally speaking, if there is no abdominal pain, irregular vaginal bleeding, abdominal drop, severe vomiting and mental disorders, it is recommended to have ultrasound examination around 50 days after conception, when the fetal heart and buds basically appear. If there is bleeding and abdominal pain, severe vomiting, etc., you can promptly go to a regular hospital for ultrasound examination to rule out the risk of ectopic pregnancy.