Intrauterine pregnancy is determined around 6 weeks of pregnancy and ultrasound is commonly used to determine intrauterine pregnancy. Ultrasound is often used to determine intrauterine pregnancy in the early stages of pregnancy. At 6 weeks of gestation, the germ and primordial heart tube pulsation can be seen in the uterus and the yolk sac can be seen during ultrasound examination of intrauterine pregnancy. Ultrasound can not only determine whether intrauterine pregnancy, but also exclude ectopic pregnancy and trophoblastic diseases, know whether the embryo is alive, estimate the gestational age, exclude pelvic mass or uterine abnormality, and determine the chorionicity according to the number of embryonic sacs. For women who have irregular menstruation or whose last menstrual period is difficult to determine, and who cannot infer the week of pregnancy based on the last menstrual period, ultrasound can estimate the week of pregnancy based on the size of the gestational sac and the length of the embryo bud or the length of the top rump. If you want to determine whether the pregnancy is intrauterine, you should go to the hospital in time to complete the ultrasound and other related examinations.