When should I expect a positive on my OPK?

Sh`Mira • Mother of two 🤞🏽 Mother of two angel babies. 👼🏾👼🏾
It's the first day of my fertility window and I I'm still getting negatives. Oddly I got a dark line, but it was still negative last week. Since then they have all been faint lines. I've been having sex. So hopefully it'll be positive soon. I ovulate Thursday.