Hi! First of all... ANYONE is welcome to post here anytime!
Secondly... I would also assume that you just missed your truly + OPK, you probably would have gotten it sometime later that second day.
I have a short surge and when I do OPKs I take them 3 times a day starting on CD10, then I take one everytime I pee once I see a line!

It is really the only way for me to catch it!
I have no issues with fertility and I always have a short surge. I have good ovulations and good temp rises, etc. So I don't think a short surge means anything.
And if you

the the night after you got the *almost* positive OPK then you still may be fine. A + OPK doesn't mean you are ovulating that very moment, it means you will ovulate usually within 12-48 hours or something like that. So your timing might just have been perfect!

to you this cycle!
And please feel free to post your questions anytime you like!
My name is Mandy, a host on this board, let me know if you need anything!