Okay. Girl power unite please!!

Hailey
So 2 weeks ago I had sex, and for some reason I am super nervous about being pregnant. I don't want to be either.. 
He used a condom, but then later we didn't use one and he didn't cum again. 
2 days ago I started my period it was super heavy but then stopped and now I am just discharging brown.. 
Note! I have been working out every day since, and it's harsh work outs. 
Could it possibly just the change from working out that is making my period different or could I possibly be pregnant... 
Thank you!