Hope, sorry I can't answer your question. I have responded to you in PAML .

I know I kept doing HPTs until I had my 8 week scan - I figured it was worth it to keep my sanity! Can you buy some more HPTs and test again? I know it's scant consolation, but it might help.

ETA I only used the OPKs until I got a +HPT, but it did work for me both times. Maybe Deb or someone can help you with the whole LH/HCG/OPK thing.