A negative ultrasound showing no fetal heart at 6 weeks does not require any special treatment and you can wait for some time before checking again. The development of the embryo is formed in 30-40 days is the sac, about 40-50 days of pregnancy, there will be fetal buds, in about 50-60 days of pregnancy to form the fetal heart, that is, in about 7-8 weeks of pregnancy to have a fetal heart, the examination of the 6 weeks when there is no fetal heart is a normal phenomenon, do not need special treatment, you can wait for 8 weeks after the checkup again. Some women have irregular periods and are often delayed, which means that the actual number of days of pregnancy will be less and the fetal heart will appear later. Each person’s situation is different, and the time of the appearance of the fetal heart may also vary. It is recommended to follow the doctor’s instructions for regular checkups, and if there is any abnormality, it should be dealt with by the doctor in a timely manner.