I am guessing it was a two day transfer? Which means you got AF (assuming that's what it is) about 12 days post ovulation. That is a pretty short luteal phase for a progesterone cycle. Perhaps your progesterone is low???

I totally know what it's like to scour the Internet for stories of hope. I pretty much do it every cycle. You just have to look over some of my old posts to read my desperate pleas for evidence that I wasn't going to get a bfn

Nothing is quite as hopeful and desperate as us IVF-ers