Help please

So my boyfriend and I of 2 years were together on Valentines day. Things started to go somewhere and long story short I lost my v card. He didn't have a condom, but pulled and finnished elsewhere. This happened twice. My problem now is that I'm experiencing brown discharge, and I'm normally irregular so I can't track my period very well. I've read that sperm can still be in precum and I'm worried I'm pregant. I've also read that brown discharge can also just be a result of rough sex. Thoughts?