So, I had sex. It was unprotected.
His head was barely inserted into my vagina, but he wasn't hard, and
There wasn't any . But my period is due in about 3 days.
Say something happened, and there was semen that I did not notice.
What are the chances of me being pregnant?
Should I stress?

Yes you should stress if you don't want to be pregnant and become a mother.

There is always a chance and all that he needed was a little early fluid that had some sperm in it. You would not be able to "see" it.

You know have to wait, till next month, you may still have this period, so you will have to wait a month to see if you miss next months or not

But how high are my chances? That's another thing I want to know

All it takes is one sperm to wiggle its way to an egg. If I were you, I'd be praying and would also change my behavior when alone with a male.