HCG, progesterone and estradiol are endocrine tests after pregnancy. If HCG in the blood is elevated to confirm pregnancy, if progesterone is in the normal range it means that the pregnancy is more normal, if progesterone is low, there is a possibility of preterm miscarriage or embryonic arrest. If estradiol is high, the pregnancy is normal. If estradiol is below 200 ng/mL, the pregnancy may be preterm miscarriage or embryonic arrest, and it is best to recheck after 48 hours. If the HCG in the blood doubles and the estradiol appears to rise gradually, the pregnancy is normal.