App wrong on ovulation? When do I ovulate?

Zoe • 🌈 Ttc after twin loss 🌈🥺

So my periods are really irregular. My period started on the 13th. Ended on the 16th. All the apps say I’m past ovulation. But the clear blue ovulation test says I am peak. When do I truly ovulate?. Peak result was yesterday at 5pm. The 24-27 were high results, then the 28th was peak. Haven’t taken one yet today. And I think my cervix feels open, but I can’t tell cuz it’s really high up and hard to feel I can just barely reach it.