Hiya,
on poas.com ( i see you've been on it

) The lady there shows a time when she almost missed a high on opk's had she not tested twice in a day.. i guess it might depend when you tested and you were nearer ov on the first one and then missed the peak. As long as you bd' the last 2 days i wouldnt worry.
Thats all the info i got, Good luck!! xxx
ps, same thing happened to me by the way, but since i also had ov cm i just went with the above info scenario.. xx