With primary ovarian insufficiency and not taking hrt, is it possible for a woman to get an occasional period?

Kinda: If you have little to no estrogen from your ovaries you should not bleed at all. But if you have some in your diet or are overweight you may have bleeding so talk to your obgyn or endocrinologist.

Well: Having uterine bleeding and having a period can be different. If you have had ovarian failure at your age, gone longer than a year without a cycle than you should go see your doc. That would be equivalent to post menopausel bleeding which requires a workup. Adipose tissue creates estrogen as well by converting adrenal hormones; this can cause some growth of the lining and bleeding. Good luck.