Most of the time, it is normal to not see the gestational sac at 15 days of IVF transfer and can be reviewed under the supervision of your doctor. In vitro fertilization-embryo transfer (IVF-ET) is an artificial assisted reproduction technique, which is operated by professionals. Generally, blood or urine HCG (human chorionic gonadotropin) test is carried out about 2 weeks after embryo transfer to confirm pregnancy, and ultrasound is done 4~5 weeks after transfer to confirm intrauterine pregnancy, so it is normal to not see the gestational sac for 15 days after transfer, and can be rechecked under doctor’s instruction. After the embryo transfer, we should continue to give luteal support therapy as prescribed by the doctor to promote the implantation of blastocysts. Also pay attention to appropriate rest, can not carry out heavy physical labor and strenuous exercise, prohibit coitus, but do not need absolute bed rest, can be appropriate activities, appropriate increase in diet and nutrition, follow the doctor’s advice on time to review.