Gemhope, my DD is one of two frozen embryos that were transferred after being frozen at the end of day two, so by the time they were thawed and transferred they were in day 3.

One had just turned to five cells and the other was 9 cells at transfer. I won't ever know which embryo became my DD, but I want to say that it really realistic and very possible to achieve a pregnancy (and a baby at the end!) from very young embryos that have just a handful of cells.

Hang in there, and remember that yes, you need the right embryo, but giving every embryo a chance in your uterus (giving them the right place to thrive and survive) no matter how many cells it is is the way to end up with that right embryo, and right now, you may have that right embryo growing away inside you!

Wishing you lots and lots of sticky vibes for your BFP, and sending lots of hope.