Is there a fetal heart, fetal bud, progesterone low, and fetal arrest?

The embryo bud appears at 6-7 weeks of pregnancy, and the fetal heart appears at 7-8 weeks of pregnancy. However, even if the fetal heart and embryo bud appear, if the progesterone is too low, the fetus will stop developing. The progesterone will gradually increase with the number of days of pregnancy. As long as the progesterone is greater than 25ng/ml in the early stage of pregnancy, it generally indicates that there is no problem.