Melatonin messed up my cycle

I took 5 mg melatonin per night for about 9 days around the middle of my cycle. I read that it can delay or bring on ovulation. My period was five days late this month (had a pregnancy scare)! Was relieved when it finally came! And now glow is predicting my cycle to be longer; hopefully that will change back after a few months. Anyone else experience something similar with melatonin or another medication?