OPK Failure

Has anyone used Clear Blue Advanced Digital and never received a Peak symbol, but continued to have sex every other day and got a BFP?

I have had 10 days of flashing smileys and no peak. Although, I had what I thought to be my ovulation cramping. I'm confused and nervous if I didn't ovulate or if these damn tests are inaccurate at determinating the LH surge.

Help!