i feel your pain is similar to what i went thru w/ my first round..... i would guess that your beta/hcg #'s are lower than they like/want to see..... do you know what your number is??? because technically - anything between 5-50 is bfp --- BUT proceed w/ extreme caution, that number needs to atleast double every 2 days for it to be considered viable bfp.......take my situation for instance --- my very first beta/hcg was 15..... so i never even "allowed" myself to get excited...... 2 days later -- stayed the same, was told to stop taking all meds that it was considered chemical.....
HOWEVER -- i don't want to sound like a complete downer ---- my doc said he's seen hcg/beta low as 7 end up in full term, happy, healthy baby!!! so it's not "impossible"!!!