Darily - I am with MIVF too so I've only done 2 day transfers. I have gotten pregnant 2 out of 4 cycles using 2 day transfers. The reason for the pregnancies m/c were because the embryos were chromosomally abnormal - nothing to do with the 2 day vs the 5 day. So as others have said, you can definitely get pregnant from a 2 day transfer. There is a stick thread somewhere on bellybelly about this topic as well - if you feel like looking for it.