Implantation bleeding? Plz help

I had sex almost two weeks ago, when I was not ovulating. (I keep track)

We also used a condom AND he pulled out as well.

Today, after he fingered me pretty roughly, I noticed a very small bit of brownish discharge -- what are my chances of this being pregnancy implantation blood ? I'm freaking myself out :/

(My period isn't due till Oct. 7th)