brown/red discharge and cramps

E.O'keefe - 16 February 2013
Okay so I have been having brown and light red discharge for 3 days now as well as lower abdominal cramps, faintness and feeling sick, I finished my period two weeks ago, 10 minutes ago I had brown/red discharge with dark clots, what could it be? I have read it can be implantation bleeding but can implantation bleeding contain clots?