I'm 42, regular as clockwork. No effect after 1st vaccination, 2 weeks late after 2nd, very heavy/painful like going back to my teens/20's, my periods have changed in the last few years but in the respect of getting lighter and shorter, always regular still though, always have been, except when pregnant. Next period was due last week, accounting for the 2 week delay, and hasn't arrived yet, no chance I'm pregnant, no contraception and no sex.
I've had issues bleeding through the mini pill and implant/injection before, but when I'm not on hormonal contraception, my periods are regular, no matter what.
The changes I have experienced in my periods, which is probably due to my age, have been gradual, this wasn't.
The only change is the vaccine, which had no effect the first time. But, the first time I wasn't unwell, had no reaction apart from a bit of a sore arm, the second time I had a bit of a temp, felt grotty, like you do when your immune system is reacting to something, and that's not normal for me. Even with norovirus and a bad dose of flu a few years ago, my period arrived with annoying regularity!
Of course, this could be a 'new' thing for me, due to my body starting to change, that my periods are affected by being unwell, only time will tell that if I come down with something in the future.
It didn't worry me, but tbh this has annoyed me. It wouldn't stop me getting the vaccine again, however that the many women who have reported these changes are being dismissed, is not a good way to get trust for these things is it?
Report side effects, be told you're imagining things.
I don't think that the vaccine itself causes the change, rather the effects it has on the body, and that affecting hormones that control menstrual cycles, but it should be taken seriously and looked into, not dismissed.
We're 7 months into this vaccine being rolled out, it's very, very early days to be dismissing things out of hand when people are reporting it.