A period after having none for a year?

I turn 59 next month. I hadn't had a period in just over a year. Never had any menopause symptoms, no hot flashes, no night sweats. Figured I just got off easy. But also figured I was finished.

Then suddenly, yesterday, I started my period. Not spotting, a regular period. How common is this? Is it likely to continue now on a monthly basis? I was pretty regular right up to the time I stopped before.