Anyone have +OpK near your AF days???

Yuri
Hi anyone experience this?
​Im in 12dpo, my Af should start this may28, but I checked for a couple of days-my opk is almost positive like the same that I got during my fertile days... I tested but BFN, im thinking that my Af will show also... Just wondering why the opk shows positive nearing my AF??? Any thoughts? Thanks girlies :)