I got my first ever positive OPK (Clearblue regular digital) today and I just couldn't help myself - I took another one. It was negative. Wondering why? Was my surge really that fast? Does this mean I've ovulated or I'm going to ovulate really soon? (I don't temp/chart by the way.) If it makes any difference (I don't think it does) the blue lines on the sticks looked exactly the same both times.

EDIT TO ADD: I have been taking the tests since CD10 and it's CD16.

The smiley was at about 3pm and I just took another one at 7pm. I peed at least once in there so maybe my pee just wasn't concentrated enough?

We are going to try tonight and for the next few days regardless but I'm just curious what's going on. Now I know why people get the cheapie sticks because it's so addictive!