Hi! Don't give up hope yet...it is still very early! I had a 3 day transfer and I didn't get a positive on an HPT until 10 days after my transfer date. Also, in all my research on message boards etc, some people get a positive blood test even if the HPTs said negative.
I know it's hard, but try not to worry. Cramping and spotting is normal for implantation. For me, the spotting was a very pale pink and really only showed on the tissue when I used the bathroom.
Best of luck to you for a BFP blood test!
Me 36; DH 35
3 natural M/Cs, 1 IUI, 2 ectopics, lost both tubes, endometriosis
12/05: 1st IVF, BFN :(
9/07: FET, chemical
11/07: 2nd IVF, BFN :(
2/08: endometrioma removed
4/08: 3rd IVF, BFP :) but beta only 34 :(