Cat is in heat with about a 2 week break

Usually, my 7 year old cat would go into heat about once a quarter. However, over the last 3 months, she has been on heat several times. It will last around a week, then subside for a week or two, then happen again.

She never leaves the house and has never had a litter before. We do have a 12 year old neutered male cat, but he has never been an issue and usually just tries to find a quiet place to rest.

This has never happened before, is it something to be worried about?