If The Embryo Didt Reach Blastocyst In Lab,does It Mean

if the embryo didt reach blastocyst in lab,does it mean it will not reach blastocyst in uterus if transfered in day 3.Please clarify doctor.I am in very much confused state.some people are saying that day 3 transfer might get blastocyst in uterus thought it might fail to go to day 5 in lab.since I have just 3 frozen embies and am not sure how many will survive thawing process.