I am just wondering this as Last month and this month my surge was so short. This month I got a positive at 7.00am in the morning, another positive at 7.00 that evening but a negative at 10.00 that night. So just over 12 hours or maybe at th extreme if the surge happened early morning maybe 14-15 hours. I read of everyone else having 2-3 day surges- what is wrong with my surge!! Does anyone know if it might mean that the egg isn't great or something like that?