Can ovulation test strips be incorrect or not work?

I have been doing them everyday since the 28th of sept and all negative even though all my apps say am fertile and have fertile Cm. Though all different apps etc are saying different fertile windows

Glow fertile window 29-2nd ovulating on the 2nd

Ovia fertile window - 28-3rd not sure when am ovulating

Huggies fertility app online - 1st-5th ovulation on 4th

Pregnancy wheel chart predicted ovulation the 5th.

Exact same info in all apps