Anyone had a false positive caused by a faulty OPK?

I have irregular cycles, I'm on CD40. I had a positive OPK, but the way the pee soaked up the result window looked funny to me, like it was struggling. I have used the same brand of OPK for ages now and I know what they look like when waiting for the result. This one looked a little odd.
A bit later I thought I had some ovulation pain, but it could have been all in my head due to the positive result. I tested again at 7pm when I got home from work and it was negative. This also makes me believe it was false because I always have 2-3 days of positive, never had only half a day. We didn't BD last night because DH is recovering from the flu and I feel like tonight will be pointless and too late.

So what do you think?


ETA: I have nothing to back up ovulation except a positive result. I never ever get EWCM.


Am going to work now so will check up tonight! Thanks ladies