I have read countless of times in the internet that the opk could detect hcg. If opk turns out to be positive when AF is due, chances are it will be a BFP. And I've read countless of times people found out about their BFP through the opk first.
Anyway, I am not putting any hopes for a BFP this month, because I just know I am not pregnant. I tested with a clearblue on 10dpo, and it was a BFN! I pee'ed on my opk, almost faint+evaporated line. So there, I can confirm I'm not pregnant.
I've lost hope and is certain AF will show up this week. But why now a dark positive on the opk?