Fasting messing up my period?? Or could it be something else?

So I've been fasting since late April. Since then, I've lost about 15+ lbs. I'm super happy about these results!!

June 16, I had protected sex. Nothing came out of it, just a good feel but nothing orgasmic.

Now... my period is late by 3 days. It just arrived, but it's super light. Almost like spotting. I'm wearing pad so it doesn't get in my underwear but it's not as heavy as it usually is.

Do you think my weight loss could be a contributing factor to my period being so off? Or could it be something else (i.e. Pregnancy, hormone imbalance?)

I'm hoping to god that I'm just imbalanced and that my body will get back on track.