After the transfer of fresh embryos, if the transfer is successful, the test is usually done in 8-10 days. A fresh embryo transfer is an oogenesis embryo transfer, which means that the transfer is a day 3 embryo. Normally, after the fresh embryo transfer, the embryo will continue to divide and develop in the uterine cavity to form a blastocyst and travel the uterine cavity to find a suitable place for implantation. Once the embryo has settled in the uterine cavity, the placental syncytiotrophoblast cells can produce a large amount of HCG during the development of the fetus, and the serum level of HCG will rise rapidly when the pregnancy is 8-10 days old. Therefore, for fresh embryo transfer, it is usually possible to detect the bleeding HCG by blood test after 8-10 days. If the time is too short, it is not always detectable and may even cause anxiety and affect the results of the transfer. In addition, if abdominal pain and severe bleeding symptoms occur during the monitoring of pregnancy, you need to seek medical attention immediately to avoid serious consequences due to ectopic pregnancy.