Bleeding a week after period!

So my period finished about a week ago and today i found a lot of brown discharge on my leg and underwear.. I get that sometimes but not as much as i got today then a hour or so later i went to the bathroom and my panty had a bit of blood on it .. Not chunky dischargey or anything just red blood.. I had sex for the first time on monday and used a comdom it didnt break im sure but yesterday i got fingered and everything was fine until now... What could this be?