Generally the gestational sac is visible at 0.2 to 0.3 mm, so a 7 mm gestational sac is visible in the uterine cavity by ultrasound, but the fetal buds and the fetal heart are not present at this time. Generally women’s early pregnancy refers to the third trimester of pregnancy, and early morning pregnancy refers to the first month of pregnancy. After six or seven weeks of pregnancy, a pregnant woman can go to the hospital for an ultrasound to check the size of the gestational sac. The growth and development of the gestational sac needs to be judged in conjunction with the menstrual cycle and HCG results. Fetal heartbeat can be measured at seven to eight weeks of pregnancy. If the heartbeat does not appear after eight weeks, it is possible that the baby is not developing well. During pregnancy, pregnant women should pay attention to diet and nutrition, eat more fresh vegetables and fruits, high protein diet. Regular maternity checkups and good examinations. It is recommended that pregnant women should consult a doctor in time if any discomfort occurs during the preparation for pregnancy, and actively treat it under the guidance of professional doctors.