Cass - my clinic will only do blasts and claim this is why they have one of the best sucess rates in the country (SIVF). You will always end up with less embryos however. But I agree that if they don't survive in a controlled situation they probably wouldn't have survived inutero.

I don't have much experience with progesterone levels, but I'm sure some other girls can help you more.

I wish you all he best in your quest for motherhood.