Help! New to OPK’s

Kaylee • 👩🏽🧔🏽 🐶🐱 TTC 👶🏽#1

So I’m new to using opks. I started testing on CD 10 and had two lines the test line was faint. The next day CD 11 it was darker but not quite positive. Then on CD 12 and today it is just getting lighter. Is it possible CD 11 I actually surged and maybe it was diluted? Can you still get pregnant without a true positive? We’ve been BD every other day just in case.. but I’m so confused