8 weeks of pregnancy belongs to the early stage of pregnancy, you can do Yin ultrasound. Early pregnancy refers to the 1st to 13th week of pregnancy, because in early pregnancy the gestational sac is small, do Yin ultrasound will not bring too much discomfort to the pregnant woman, resulting in miscarriage and other situations, and abdominal ultrasound is not as clear as Yin ultrasound, so in early pregnancy can do Yin ultrasound. Mid-late pregnancy refers to the 14th week of pregnancy until delivery, when in mid-late pregnancy, vaginal ultrasound may bring discomfort to pregnant women, easy to trigger contractions, etc., to increase the possibility of miscarriage with preeclampsia. At this time, the uterus enlarges beyond the pelvis, and abdominal ultrasound can provide a clear view of the uterus. However, if you need to check the length of the cervical canal or evaluate the position of placenta previa, vaginal ultrasound is still needed. Consult your physician for more information about the specifics of this test.