The three pregnancy tests look at the results and focus on the dynamics of the three lab results – HCG, progesterone, and estradiol – after pregnancy. 1. HCG: also known as human chorionic gonadotropin, generally changes at a relatively rapid rate in early pregnancy. If there is a drop or rise too slowly, it should be considered that the quality of the embryo is not good, or some will be ectopic pregnancy, or biochemical pregnancy. 2. Progesterone: Progesterone can fluctuate in early pregnancy rather than rising every time. Because the secretion of progesterone itself is pulsatile, generally as long as it is not too low, it is not significant. 3. Estradiol: Estradiol is a relatively sensitive test, if there is a drop in early pregnancy, it usually means that the quality of the embryo is not good, or there may be ectopic pregnancy. Laboratory tests may have small errors, especially those done in different hospitals, so it is recommended to seek medical advice as soon as possible if you are not feeling well.