holding pee

so i know it's best to take opks in the late mornings but i just cannot hold my pee in the mornings..i don't even drink much usually a can of dr pepper but not fast usually takes a couple hours. i pee like 4-5 times just between the time i wake up and afternoon and besides the fmu it's all super super light and my opks barely have a second line at all i'm thinking because my pee is almost clear looking. i did do a second one yesterday around 5pm and even tho it wasn't positive it was a lot darker than the afternoon one i did that was so faint it almost wasn't there. i'm on cd 14 now so i'm hoping i didn't miss my positive or maybe i just won't ovulate this month..anyway will it be ok to take them in the evenings? hopefully i don't miss my surge if i have one at all