Question: what is day of embryo transfer?
Answer: During the days after a transfer, the following happens to the embryo: Day 1: The blastocyst begins to hatch out of its shell. Day 2: The blastocyst continues to hatch out of its shell and begins to attach itself to the uterus. Day 3: The blastocyst attaches deeper into the uterine lining, beginning implantation.