In a person with normal menstruation, the gestational sac can be observed under ultrasound on the 40th day of pregnancy, but it is not very clear. At 35 days of menopause, a round gestational sac can be observed in the uterine cavity by ultrasound, and at 6 weeks of gestation, the embryonic bud and primitive cardiovascular pulsations can be seen. Usually the main purpose of ultrasound in early pregnancy is to determine intrauterine pregnancy and to exclude ectopic pregnancy, trophoblastic diseases and pelvic masses. However, in the case of irregular menstruation, the pregnancy sac may not be seen in ultrasound examination after 40 days of menopause, and then it is necessary to combine blood and urine HCG and clinical symptoms to make a judgment. If women of childbearing age with a history of sexual intercourse experience menopause or abnormal menstruation, the possibility of pregnancy should be considered, together with the blood or urine HCG test, a positive test suggests pregnancy, and ultrasound finds intrauterine gestational sacs or germs can be diagnosed as intrauterine pregnancy, and the observation of primitive cardiovascular pulsation suggests that the embryo is viable. When the embryo develops to about five months, a large color ultrasound can be performed to observe the fetal development with or without abnormalities, and with the changes in fetal growth and development, ultrasound can be checked once a month or so. In addition, during pregnancy, it is necessary to maintain a comfortable mood, eat a balanced diet with nutrition, eat more fresh fruits and vegetables, and maintain a moderate amount of activities, and regular maternity checkups, which can help pregnant women to pass through the pregnancy smoothly.