Pregnant women in 40 days of pregnancy B ultrasound can clearly see the gestational sac in the fetal part of the organs, buds and heartbeat, this time the gestational sac in 2cm or so, and the gestational sac of the fetus grows to 1cm or so, has been able to initially line into the shape of a human being. At this time is just pregnant women began the early stages of pregnancy, fetal status is not stable, this stage couples should try to avoid cohabitation, pregnant women should also pay attention to maintenance do not strenuous exercise. And most of the time is not recommended to do ultrasound, but if the patient side of the strong request or pregnant women appear vaginal bleeding, abdominal pain abnormalities and other special circumstances, you can choose ultrasound to check the development of the fetus in the abdomen.