Clear blue digital OPK?

So I used the opk clear blue digital last month and got the expected couple days of lows,couple days of high, and then the solid smiley indicating peak fertility and I had EWCM, but unfortunately we were unable to DTD on peak days and lessened our chance of conceiving. However this cycle were back at it again, and I started a few days earlier since I had extra sticks. Anyway I usually don't ovulate until cd18 but I started testing on cd12 & cd13 which revealed low fertility and then yesterday cd14 I got the solid smiley, peak fertility and totally skipping high fertility! I also do not have a high soft cervix yet nor much cervical mucus. We DTD anyway but I'm wondering if anyone else has had this happen or is it a defect in the test? But now I can't test with the holder anymore because it shuts off after reaching peak.