Period starts with fast?

So I've noticed something really weird about fasting for me, and I want to know if anyone else experiences it. Theoretically, fasting should halt a woman's cycle, not start it, but every time I start up a fasting regimen again after being off of it for a couple months, my cycle starts on day 2 after not existing for MONTHS. If I stay on IF, I'll continue to have a decently heavy flow monthly (like a normal person) until I stop IF. Additional info - I switch between daily 16:8 & 20:4, with weekends off. I also have a hormonal IUD. I wonder if because the IUD stops your cycle by raising hormones, and fasting lowers your hormones, I'm just cancelling out the effects of both.

Answer

I had to stop a fast once because I realize I hadn’t gotten my period was 4 days late (I’m never late) took a negative pregnancy test, broke my fast & got my period a day later…so yes hormones will be impacted by fasting…I’ve heard that hormones can be stored in adipose tissue & when you fast & ur body starts breaking down fat then those hormones get released (if it starts for u on day 2 that’s probs when ur body goes into deep ketosis & fat burning) I could be totally wrong though! After my delayed period I did research & learned you’re not supposed to fast right before ur period so now I’m being better about timing mine, but I don’t know in ur case since ur not getting regular periods itd be so hard to time … very curious!