A vaginal ultrasound in the 6th-7th week of a woman’s pregnancy can reveal fetal buds and fetal heartbeats, but there are individual differences. The timing of the appearance of fetal heartbeat and fetal bud is closely related to the usual menstrual cycle of the pregnant woman. For women with regular menstruation, a vaginal ultrasound in the 6th week of pregnancy can reveal the fetal bud and the fetal heart can be seen in the 7th week of pregnancy. In some women, delayed ovulation leads to delayed conception, which causes delayed development of the embryo. Generally, the appearance of fetal buds and fetal heartbeats can be delayed by 3-5 days, and in some women, the fetal buds and fetal heartbeats can appear as late as 60 days of gestation, i.e., the 8th week of pregnancy. If the menstrual cycle is short and ovulation is early, the germ and fetal heart can be detected as early as 30 days after pregnancy. Pregnant women are advised to visit the obstetrics department of the hospital regularly for vaginal ultrasound and blood HCG tests after pregnancy to ensure normal growth and development of the embryo.