Can someone please explain to me what's this?

So AF is due in 4days but I've been having what appears to be fertile cervical mucus AGAIN. I got a positive on a digital opk on June 7th around noon and another on June 8th in the a.m and everyone after was negative so I'm sure I ovulated around then. I took another digital opk today but of course that's negative. Any idea what's going on?