What Causes Light Spotting After Having Prolonged Periods?

I have recently been on my period for over two weeks now, however now when I go to the bathroom I'm clear when I urinate and my towel is clear but when I wipe there is a presence of bright red blood. Could this still be my period or something more serious. I previously have had a severe kidney infection, and since then have tried to keep my fluid intake up. But I'm worried, and can't see my gp for two more days.