The normal value of estradiol at 7 weeks of pregnancy is around 1000-2000 ng/l. The level of estradiol increases moderately after pregnancy, which helps to thicken the endometrium and facilitates the embryo’s implantation and growth. In the 7th week of pregnancy, it is necessary to check not only estradiol but also chorionic gonadotropin and progesterone levels in the blood to see if they are in line with the gestational cycle, and to check the size of the gestational sac under the gynecological ultrasound, which will be around 2 cm with primitive heart tube pulsations, to prove that the early embryo is developing well. In the third month of pregnancy, women often have unstable embryo implantation, so they need dynamic testing of chorionic gonadotropin, progesterone and gynecological ultrasound to avoid preterm abortion.