I had sex two days before I got my period, it was light and then heavy and then light again and it lasted 2 days longer than normal. Which it usually is very heavy then very light and gone on the fourth day. Now this month my period is a week early and I have been spotting for the past three days. Could I be pregnant?

If you had sex you could be pregnant. Go to the store and buy a pregnancy test.

The only way to be positive is to take a HPT with your first morning urine. Anytime you have unprotected sex you can get pregnant no matter when in the month you have sex. I doubt you are pregnant and still having your period, no matter when your period is coming. It is rare for a woman to continue to have her period while pregnant.
But to ease your mind go buy a test, that is the only way to know for sure.