Long time, no hassle!

Just wanted to ask your advice on something that is bothering me.
I'm 2 days into my 2ww (going nuts already..). I had 9 mature eggs collected and 6 fertilised (we're using donor sperm this time. DH has azoospermia and high FSH so low chance of a BFP with his sperm apparently..

We were planning to take our embies to blast, but on day 3, there were 2 clear leaders so we decided to go with the 3 day tranfser. By day 3, we had 2 grade 1's (7 cells each) a grade 3 (4 cell) & 3 grade 3's (6 cells each). Grade 1 is the best by the way and 4 is the worst so it made sense to transfer the 2 grade 1's (7 cells) rather than risk taking them to blast.
The embryologist was very happy with the 2 7 cells that were transfered. Apparently, there was very little fragmentation (none at all on one of them) and they were developing at just the right speed and rate for day 3. (I am a bit concenred that they were 7 cells and not 8 cells on day 3, but I worry about everything - do you think this makes a diffence to successful outcomes?)
Anyway, we decided to culture the remaining 3 grade 3's (6 cells) to blast as they weren't good enough to freeze on day 3 due to their fragmentation (grade 3 means quite bad fragmentation, although not hideously severe). Spoke to the embryologist this morning and 2 stopped dividing at the 10 cell stage and 1 is apparently "trying its hardest" to become a blast although its got quite bad fragmentation and probably isn't going to be good enough to freeze.
I'm now worried that these 2 inside me never stood chance to make blast either. If the other 4 didn't, why should these be any different? The embryologist said that the 2 put back were considerable better quality than the others so she would hope that they are thriving. The fact that a grade 3 was "nearly" at blast (albiet poor quality) should be encouragment that a grade 1 from the same batch should be "dividing &
conquering" no problem.
Sorry for the ridiculously long post. Can you give me your opinion on this?
Thanks Ghost.
Love, Corinna xx