The normal value of HCG is 0-5mIU/mL and greater than 5mIU/mL confirms a pregnancy. Monitoring the HCG level and finding a tendency of doubling of HCG will confirm that the embryo is well developed and active. However, it is not enough to check the blood HCG, but an obstetrical and gynecological ultrasound is also needed. The main purposes of ultrasonography are: 1) to determine the pregnancy in a normal position in the uterine cavity and to exclude the possibility of ectopic pregnancy; 2) to exclude the possibility of gestational trophoblastic disease; 3) to determine the development of the embryo, the size of the gestational sac and whether the time of appearance of the fetal bud and fetal heart corresponds to the number of days of menopause through ultrasonography.