TTC for a few months now No luck. 36F 35M

We have been trying to conceive for a few months and no luck. I’ve been using this app and another app (Ovia) to track my fertile days along with CB digital ovulation tracker but usually the tracker tells me something completely different from the app. The CB tracker tells me I’m in my peak around CYcle Day 9-12, but the app says day 13-15. I thought the app is what’s making us miss our opportunity so I started going with what the CB tracker tells me but still no luck. CB tracker would tell me “low” for a couple of days and it peaks all of a sudden for two days and drops to negative.

Does this mean I’m probably not ovulating?

My cycle shifts anywhere from 28days to 34 days. Every month is different so it’s very difficult to see a pattern.

Our first child was so easy to conceive. I was 33 at the time and we nailed it the first try.

Seems like that’s not the case this time around.

Any tips on how to track my most fertile day??