A drop in progesterone on day 8 compared to day 5 of the transplant may be normal or the transplant may have failed. In the early stages of a woman’s pregnancy, the secretion of progesterone is pulsatile, and the value of progesterone fluctuates when blood is drawn at different times of the day. On the 8th day of the blastocyst transfer done, the blood test for progesterone is lower than that on the 5th day, if this value is still above 20ng/ml now, this may be a normal phenomenon, because this value itself will fluctuate. For this situation, it is recommended to test with early pregnancy test paper or pregnancy stick about two weeks after blastocyst transfer, or directly draw blood to check HCG. If the blood test for progesterone is very low on the 8th day of blastocyst transfer, for example, below 10ng/ml, it is very likely that the transfer has failed, that is, the blastocyst implantation is unsuccessful. It is recommended to go to the hospital in time for examination and follow the doctor’s instructions for appropriate treatment.