Possible to get a "late bfp" even tho you ovulated on time?

I ovulated cd 15 per my opks but I'm still getting BFNs and af is due today or tomorrow. Could I still be pregnant? Or since I know I didn't ovulate late I'm def not? Had cramps earlier in week, but now nothing. Fatigued. And I'm still having CM. When normally, my cm dries up to nothing when AF is about to hit. Thoughts?