Ultrasound can be used to check for pregnancy through abdominal ultrasound and also through vaginal ultrasound. The main points to look for are: 1) whether the uterus is enlarged, 2) whether the gestational sac is visible in the uterus, and that the yolk sac can be found in the gestational sac at about 35 days of pregnancy, the gestational bud at about 6 weeks of pregnancy, and the primordial heart tube at 7 weeks of pregnancy. According to the different weeks of pregnancy, the ultrasound will clearly examine whether the current state of menopause matches the size of the gestational sac, so that a preliminary diagnosis can be made as to whether the embryo is still developing normally.