Period?

I got my period today, 2 days earlier than expected. I'm usually really regular and can almost track it to the second. We had unprotected BD around the time I was expecting to ovulate. My cramps are stronger today than what they usually are. I don't track my ovulation to the point of testing nor have I taken any kind of test this month. I'm having one of these evenings where my thoughts are running and I kinda need a vent. Could it be possible that this period is a miscarriage from a chemical pregnancy? Or am I just overthinking things?