I am one of those women affected by it. I had pf1zer--dose 1 on 1/18/21 and dose 2 on 2/8/21. My both doses occurred within one cycle, which should have ended about a week after my first dose but did not end until 2/12/21--a 48 day cycle. (My normal is 27-29 days). Since then, my cycles have ranged from 25-48 days. Every time I think they've regulated after a couple normal length cycles, a long cycle pops up. I've NEVER been this irregular, even as a teenager I was incredibly regular. I'm only 34, so pre-menopause is highly unlikely.