Why are my levels so low??

My first month ever using OPKs. Everyone else’s tests I see, their levels are way higher than mine. Am I testing at the wrong times?! I take the pic at the 5 minute mark except the really dark one on CD 11, that was hours later cuz I forgot about it, so I don’t think that is a true positive since it’s dry? I’m supposed to ovulate Sept 3 according to this app.