Chemical Pregnancy on 4AA Fresh Transfer

I am 31, husband and I did IVF due to previous cancer treatment, so we were using his previously banked frozen sperm. Found out along the way that I had a blocked tube thru HSG but otherwise all bloodwork great, SIS clear, neither of us have any conditions. We did mild medication, got 9 eggs, and 4 day 5 blastocysts. 3 were 4AA, 1 4AB. We are “ideal candidates” and my first beta from first fresh transfer came back at 6, yesterday was told it was under 5 and chemical pregnancy. We are shocked. Totally expected first round to work out for us due to our circumstances and everything going so well up until this point, but learning that IVF really is not a guarantee no matter what.