The time of appearance of fetal heartbeat and fetal bud is usually 6-8 weeks of pregnancy, so the absence of fetal heartbeat and fetal bud at 6 weeks of pregnancy is mostly normal. However, in rare cases, the absence of fetal heartbeat and fetal bud at 6 weeks of pregnancy may be a sign of embryonic abortion.1. Normal: In women with regular menstruation, i.e. women with each menstrual cycle of 28-30 days, fetal heartbeat and fetal bud can usually appear at 6-7 weeks of pregnancy, while in some women with irregular menstrual cycle or women with each menstrual cycle of about 50 days, fetal heartbeat and fetal bud may appear only at 8 weeks of pregnancy. In addition, delayed ovulation and late implantation due to recent overwork or emotional ups and downs may also lead to late appearance of fetal heart and fetal buds; 2. abnormal: in rare cases, no fetal heart and fetal buds appear at 6 weeks of pregnancy, or even no fetal heart and fetal buds after 1-2 weeks of observation, and poor doubling of blood HCG during the period, which generally indicates embryonic arrest, usually due to chromosomal abnormalities, viral infections and poor sperm quality. It is usually caused by chromosomal abnormalities, viral infection and poor sperm quality. Therefore, if there is no fetal heartbeat and fetal bud at 6 weeks of pregnancy, it is recommended to wait for observation and ultrasound examination after 1 week, usually until 8 weeks of pregnancy. If the blood HCG test is good, it is usually not embryonic abortion and pregnant women should not worry too much.