If the blastocyst is detected by ultrasound, the blastocyst can be seen by vaginal ultrasound and the size of the embryo can be measured at about 5-6 weeks after menopause. The exact time to see the blastocyst varies depending on the length of the menstrual cycle and the growth rate of the embryo, but it is usually no more than 60 days at the latest. If the blastocyst is detected by taking the pregnant woman’s blood to test for human chorionic gonadotropin, it can be detected about one week after the embryo has been implanted, which is equivalent to about three weeks after menopause. In the case of blastocyst transfer, the time of detection is not much different from the normal time of conception, and if it is not detected, the test can be postponed for a few days.