IF can 100% mess with your hormones/menstrual cycle. Missed periods, early periods, late periods, unusually light or heavy periods… You can experiment with different approaches to see which works best for you personally (e.g. 20:4 hour fasts 7 days per week vs. 36 hour fast once per week vs. whatever else), but if there’s a particular approach that feels good to you but seems to have a negative impact on your period then I’d suggest (from personal experience, not a medical background) giving it a few months to see if your body adapts.