Period MIA, been fasting?!

Hi everyone. I’m about 8 days late on my period, and I’ve never had a late period before. I’m 25, and I’ve been fasting about 18-20 hours a day for 11 days now. I wasn’t sure if it was due to the fasting that I’m late, or another thing. I’ve also been taking Vitamin D supplements once a week for 3 months and using boric acid suppositories as needed. Does anything in particular sound like it may impact my cycle? I am not worried about pregnancy being a possibility. Thanks for your thoughts