what the frickin hell, man?!?!

So I got a positive opk 10 days ago and then of course they went negative again. Well after they went negative, I started cramping and thought maybe I miscalculated my O date and the cramps were possibly ovulation pain so I took another opk which was suuuuper dark. Well now my opks have been super dark for 5 days now. Five bloody days. I never have five days of super dark opks. What gives? I've gotten vfls on blue dye and a bfn on a Walmart pink cheapie. Any thoughts?