My understanding of a 5 day transfer is something called a blastocyst. If you have enough fertilized eggs and they are all developing well (at least 8 cells) They will often go past day 3 and wait until day 5 for transfer. Here is a link with info on blastocyst.
http://www.advancedfertility.com ...

Hi there,

This is my first time posting. I am half way through my 2ww. Trying not to think about it too much and hoping this next week will go by fast. I have the usual symptoms as well from the progesterone injections. Don't feel any different otherwise. This is my 3rd IVF cycle. 1st one was a ...