The lack of breast swelling a few days after frozen embryo transfer does not necessarily mean that there is no implantation, but also in conjunction with laboratory tests to confirm. Frozen embryo transfer is a method of in vitro fertilization-embryo transfer technique, which is operated by professional physicians. After successful implantation, the hormone level in the body rises, and reactions such as nausea, vomiting and chest swelling may occur, but some pregnant women may not have any reaction, so when the chest is not swollen for a few days after the transfer, it may not necessarily mean that the embryo has not implanted, but also combined with the blood level of HCG (human chorionic gonadotropin) to determine. Blood HCG starts to be secreted about 1 day after the embryo has successfully implanted, and when the blood HCG test is positive, it means that the implantation has been successful, and ultrasonography is done at 4~5 weeks after the transfer to confirm intrauterine pregnancy. It is not necessary to have absolute bed rest after transplantation, you can have appropriate activities, but not strenuous exercise and exertion. It is also necessary to increase the diet and nutrition, and continue to follow the doctor’s instructions to give luteal support therapy.