The optimal time for implantation after frozen embryo transfer is related to the woman’s body type and the type of frozen embryo, etc. It needs to be analyzed on a case-by-case basis and cannot be generalized. For day 3 embryo transfer, the best time to implant is usually 3-5 days after the transfer; for day 5 blastocyst transfer, the best time is 2-3 days after the transfer. For some women, due to their physical condition, the time of implantation may be delayed, which may be 3-7 days after the transfer, or 7-14 days after the transfer, which is basically normal and no need to worry too much. It is generally recommended that women should go to the hospital’s fertility center for a blood test about half a month after the frozen transfer to determine if the pregnancy is successful by checking the blood HCG level. During the period of frozen embryo transfer, you should take more rest, get enough sleep, do not overexert yourself, avoid strenuous sports and physical labor, do not have sex, and keep a happy mood.