It was our first transfer, we opted straight for FET over fresh. I could feel my lil embie burying itself, I told DH that it was on my left side and then my scans confirmed it. I found this which may be helpful to you:
Day 1: The blastocyst begins to hatch out of the shell – this is called hatching. The cells will carry on dividing throughout this process.
Day 2: The blastocyst continues hatching and begins to attach itself to the uterine lining – this is an incredibly important part of the process.
Day 3: The blastocyst attaches deeper into the uterine lining and implantation begins. It’s perfectly normal to experience some bleeding or spotting around this time and it’s not a cause for concern.
Day 4: The blastocyst digs deeper into the uterus and attaches to the endometrial blood supply. Some people experience more bleeding at this stage, but a lack of bleeding or spotting also doesn’t mean that it has not been successful.
Day 5: Implantation is considered complete and the embryo is developing, along with the cells that will eventually become the placenta.
Day 6: Placenta cells secrete hCG (human chorionic gonadotropin), which is the hormone picked up in pregnancy tests. The hormone triggers increased progesterone release in the first trimester to enrich the uterus lining and sustain the growing embryo/foetus.
Day 7: The embryo is now a foetus and yet more hCG is present in the blood stream as the placenta continues to develop.