Ellie,

Thaw rates for blasties are better than for Day 2. No one can gaurantee they will thaw of course, but blasts are more robust in general. If they survive the thaw, the chance of success is comparable to a fresh transfer! So please don't stress, my sweet.

Also, on the aside, a blast frozen from a cycle that previously resulted in a pg is more likely to result in another pg. Just FYI.

ETA I know of plenty of women (not necessarily on BB though) who've had their bubs from blast FETs, too!