No day 5 blasts frozen

Hi, I am 32 with surgically excised stage 4 endo and DOR due to the surgery. I am on my first round of IVF. I had 10 retrieved, 7 mature, 6 fertilized (via conventional insemination after embryologists confirmed normal appearance), and my report today said 0 day 5 embryos were biopsied and frozen. We plan to do PGTA testing for any blasts.

I was worried about cycle failure, so I messaged again and the lab responded that “4 of the embryos are in a stage we would normally expect to see today, but need to progress further to qualify for the biopsy procedure, and 2 others are in the multistage stage, which is a stage we normally see on day 3, so they are considered behind developmentally.”

My question: is this normal, and is it possible that any of the 4 will become day 6 blasts? My clinic never prepared me for this possibility on day 5, so I’m not sure how worried I should be about getting 0 blasts in total.