That was one of the symptoms I had that I now recognize as being a flag. I'll tell you the time line of things in case it helps you with clues to what is going on with you.
For most of the years from my early 30's to around 45, I had periods only every other month and sometimes every four months. I think it connects to a similar incident in my early 20's when I missed a period for several months and the pregnancy tests were negative. The doctor gave me an injection of something to stimulate one of my ovaries into releasing an egg. She said the ovary surface had hardened and eggs were unable to make their way out of the follicles. My periods were regular after that until my 30's.
Coincidentally, in my 50's that's the same ovary that had the huge cyst growing on it that became life-threatening due to the size of it.
What was unusual was that for about 5 years before that, I suddenly started having regular monthly periods again. One of them was very light while the other was heavy and painful. Eventually, they both became more frequent and very heavy and I had to fight anemia. In the year before my hysterectomy, my periods suddenly stopped completely and the cyst started rapidly growing.
I often wonder if those trapped eggs in the follicles are what eventually became cysts.