I never get a positive opks...

I tried dipsticks, and with those you can see the line progress. But never a clear positive.

I tried ClearBlue digital opks, I would always get a flashing or empty circle. No solid smilie face...ever. I even bought the CBFM with no success.

I tried temping, but that was a complete mess. My temps were always all over the place with little to no consistency.

Why am I not getting positive opks?