The appearance of the fetal heart and fetal bud is more related to the woman’s menstrual cycle. Usually, the fetal bud and fetal heart can be observed in the uterus on ultrasound at about 6-7 weeks of pregnancy. For pregnant women with regular menstrual cycle, fetal heart and fetal bud development can appear around 5 weeks, fetal bud can be observed under ultrasound at 6 weeks, and fetal heart development can be observed around 7 weeks. For pregnant women with irregular menstrual cycles or who have forgotten their last menstrual period, the timing of the fetal heartbeat and fetal bud can be observed by ultrasound to project the last menstrual period and the expected date of delivery. For women with delayed menstruation, there may be delayed ovulation and they need to wait longer to observe the fetal heartbeat and fetal bud. If the fetal heartbeat and germ are not observed after 8 weeks, it is necessary to consider the possibility of abnormal embryonic development and go to the hospital to have blood tests for HCG and progesterone. It is often recommended that pregnant women undergo the first ultrasound examination at around 6-8 weeks to determine the gestational sac and to rule out ectopic pregnancy.