Ultrasound can be performed at 6 weeks of pregnancy, i.e. around 42 days of menopause. This is because at 6 weeks of pregnancy the ultrasound not only reveals the gestational sac, but also the germ and the primordial ventricular pulsation, which will allow you to know whether the pregnancy is intrauterine or not, as well as to determine the development and survival status of the fetus. If you have abdominal pain or vaginal bleeding before then, you should always consult an obstetrician and gynecologist. In early pregnancy, some pregnant women may experience bitterness, nausea, vomiting, coldness and drowsiness, which are normal early pregnancy reactions, and some pregnant women may have mood swings, which mostly disappear on their own around 12 weeks of pregnancy. During this period, you can make appropriate adjustments according to your preferences, pay attention to keeping warm, and insist on taking oral folic acid to prevent fetal neural tube abnormalities. It should be noted that after ultrasound confirms intrauterine pregnancy, another ultrasound examination is recommended between 11-13 weeks + 6 days of gestation for early pregnancy fetal NT, which is more significant in screening for early fetal chromosomal abnormalities.