Diana just wanted to say don't give up, my cousin went through IVF and her levels rose on the low side, but at her 8wk dating scan there was a nice strong healthy HB, and they dated her 5 days later than expected. So just because they know your transfer date, doesn't mean they know your implantation date, so it could be a little lower if bubby implanted a little later. I hope I didn't confuse you! Good Luck.