Is two people rubbing their bodies together considered a sex act?

Me and my boyfriend were dry humping with no clothes on and we were a little rough. its been 4 days since then and for some reason I have been spotting. I doubt it is my period because I'm not showing my usual cramps or other symptoms. Although I do get my period around this time during some months. Also the spotting is a reddish brown color... I'm scared that I might be pregnant...what is going on??