Ovulation tests not matching app predictions?

Has anyone used ovulation tests strips to track ovulation and they sort of aren’t getting darker? I’m meant to be cycle day 14 and haven’t had any sort of positive ovulation test. Only just started getting cramps today and my tests are sitting at 0.58 at the moment. Yesterday was 0.49. Idk what’s happening. First pregnancy happened so easily and this is 3rd month trying for number 2. Last month’s tests peaked but we weren’t successful. I have had a lot of stress in the past week. Does that contribute to delaying ovulation? Someone please help me work out what’s going on 😢