Tracking periods/ovulation

Wondering who tracks their ovulation and how accurate it is according to the app?? My period has only become regular in the last year since giving birth/stopping breast feeding but the app is pretty accurate within a day or 2 for my period to come. I've become very aware of my body and the signs its giving me but I am currently 5 days late. According to App I would ovulated first week of February which Is when it always says i do. I had sex Feb 15th but still no period. Is it possible to ovulate different times every month??? I'm not actively TTC so I've never really tracked ovulation but now I'm wondering where my period is and if its possible that my ovulation is off I'm pregnant 🤔