The lack of fetal heartbeat around 12 weeks of pregnancy can be caused by a short pregnancy or an empty sac. Generally, if the menstrual period is regular, the fetal heart can be seen around 6-8 weeks of pregnancy. So if you have regular periods and you don’t see a fetal heartbeat at 12 weeks of pregnancy, consider an empty sac, which is clinically known as embryonic arrest. This may be caused by the poor development of the embryo itself or genetic mutation. If the patient’s menstruation is not regular, and it takes several months for the patient to have a menstrual period in the long run, it is also possible that the actual duration of the pregnancy is relatively short, resulting in the fetal heart not being seen at the moment. It is recommended that the size of the gestational sac can be seen through the pelvic ultrasound to see the actual size of the gestational sac, if it is still within 8 weeks, it is recommended that the blood HCG and progesterone can be rechecked, and the pelvic ultrasound can be rechecked again in an interval of 5-7 days to see if there is a fetal heart. If you can’t see the fetal heart, then consider the possibility of embryonic failure and need to be treated under the doctor’s supervision to avoid vaginal bleeding.