Spotting???

Hey so I got off my period like 2 weeks ago. but I've been more stressed than every lately just crying over my ex and the drama that has come along with the breakup and such. but as of these past few days I've had some brown spotting. is it possible that it's just from stress? or is it more likely implantation bleeding bc I've had unprotected sex recently (he pulled out)?? I'm freaking out. someone help me understand what's going on with my body