When I first tried OPKs a while back, I only did them once a day, and I never saw a positive. So, I'm guessing that two a day is what works best, and since you only have 11, that'll run you out really quick. But if you're seeing EWCM, you should probably start watching for O. If you don't want to use your OPKs now, then you could at least BD freely, to cover your bases. Then, start using your OPKs at the time that you usually do, and if you don't get a positive, then you can maybe assume that you DID ovulate earlier that you tested. But, if I were in your situation, I would just BD all the time, anyway, so OPKs wouldn't matter!

That's why I don't use them.
But yeah! I say get BD'ing!