Brown spotting

So I’m on nexplanon and my period is 2 days late but last week I had dark brown spotting/small clots (didn’t even need a pad it was so light). I have unprotected sex regularly without a condom( bf does pull out) but I read this could be a sign of implantation and now I’m being paranoid! Someone tell me not to worry please. My chin and forehead is breaking out to but that’s normal for me and I’ve been cramping some but nothing unusual