App vs. LH strips? Please help me.

Call me Cris 😜 • Life is what you make it 🙃👍🏼

The app says I’m in my fertile window and that I’m due to ovulate in two days. But all my LH strips are coming back with a faint line indicating a clear negative.

Could I continue to get faint lines up until O day? Or is it supposed to be getting darker already?