In early pregnancy, the blood HCG and progesterone tests are used to understand the development of the embryo. If the blood HCG does not rise significantly every other day, but the progesterone decreases, the possibility of ectopic pregnancy must be clinically excluded. Ultrasound examination is recommended to understand the location of the gestational sac, and hospitalization is recommended to further understand the rise of HCG and progesterone through hospitalization and to determine whether the pregnancy is intrauterine or ectopic based on the location of the gestational sac in the ultrasound examination. If there is a doubling of HCG but a decrease in progesterone, intrauterine pregnancy is more likely and may be caused by progesterone deficiency. Insufficient progesterone can cause contraction of the smooth muscle of the uterus and lead to preterm miscarriage or abortion, so oral progesterone is recommended for treatment after intrauterine pregnancy is confirmed.