If you are pregnant with a fetal heart, is the embryo stable?

After implantation, fertilized eggs will gradually divide into multicellular gestational sacs. After more than 30 days of pregnancy, each primitive cell will differentiate and slowly form a embryo, and the embryo will further develop to form a fetal heart, which is a process of fetal formation. The time to see the embryo of fetal heart during pregnancy: generally, the embryo sac is formed in 30-40 days, the embryo is formed in 40-50 days, and the fetal heart is formed in 50-60 days.