When did I ovulate!?

Ronnie

So I’m slightly confused what to go by for when I have ovulated because my body felt like it happened on the 25th because I had aches twinges headache & EWMC but clear blue OPK said I was at the peak on 29th and the <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a> said I would ovulate 31st l.. don’t know how to work out how many DPO I am 😬