Help! Always negative OPK

I use both Glow and Flo and (probably because my periods are never exact) the ovulation prediction is never the same. I tested the entire week and twice on the days that overlap from the app predictions, but never had a positive opk.

My first baby was a surprise. I was diagnosed with PCOS years prior and was on BC when I found out I was pregnant. Post baby my periods are much closer to regular (within a few days of expected) but he is 3 1/2 and I haven't been able to conceive again yet. My husband wants to cut off trying within a year, so I just started using OPKs and have an appointment with my OBGYN next week.

Any similar experiences??