Freaking out

Stephanie
Hey guys. Huge TMI.
I fooled around with my boyfriend without protection ( he basically put something somewhere a few times but didn't finish) and 6 days later I'm spotting. My period is due in a week and I'm spotting brown CM. I don't have any other symptoms really besides cramping. Could this be implantation bleeding? Also, I just stopped being a vegetarian last week and started eating meat again...could that have brought my period on early? 
I know I messed up by not using protection but I'm definitely getting birth control ASAP. I just don't know what to do. I can't test yet and I'm freaking out. Please help!