Not sure when to track ovulation?

Im 35, and went off birth control almost a year ago, after being on it for a very long time (10-15 years).

My period used to be very regular, and now since coming off the pill, I seem to have a light period for a week (maybe spotting?) and then bleed a bit heavier for a week.

When should I track my period starting? In terms of trying to track when I’m ovulating. I don’t know how long is normal for periods to go back to normal? Thanks in advance!