Does anyone ovulate earlier/later on in their cycle than they are supposed to?

I feel like I ovulate early considering my cycles are normally very irregular (3-9 month apart sometimes) but I’ve had two ‘normal’ 30 day cycles and now coming up to my ovulation and my cervix feels low and closed but last week, not long after my period stopped it felt high and open. It’s just so hard to figure out when my periods are so irregular then can be ok for a few months.

Just wondered if anyone else experience this.