Please help please i just dont wanna miss my surge

I was having cramps today mild and more cm but not by much it was white/ clear and very slippery ive been taking opk and the 24th which was CD 12 looks the darkest but not a positive and its been fading ever since tested two times a day​should i keep teating has anyone went from faint to darkish to faint then get pos?? Glow said my ovulation day is the 27th which is two days away someone please explain!!!!