Blastocysts can implant when they are about 2-3 days after transfer, but there are individual differences. Generally blastocysts can implant at 2-3 days after transfer, but not every blastocyst has a chance to implant. Not all blastocysts will successfully implant after blastocyst transfer, and the uterine lining has to be prepared for synchronized development. An endometrium that is not adequately prepared, or that has a problem with the window for implantation, is not sufficiently tolerant and will not be able to conceive. If the blastocyst is successfully transferred, a substance called human chorionic gonadotropin is gradually secreted, and the amount of the hormone secreted changes from less to more, and eventually reaches a level that can be detected in the blood and urine, only then does the treatment process pay off. After blastocyst transfer, we should continue to give corpus luteum support as prescribed by the doctor to promote the development of blastocysts and to facilitate the implantation, meanwhile, we should pay attention to proper rest, and usually conduct blood or urine hCG level test to confirm whether the implantation is successful or not at about 10-14 days after the transfer. And ultrasonography can be done after 4-5 weeks to confirm intrauterine pregnancy.