Should I Take Keflex To Deal With Drainage From Cellulitis?

I had a lump under my breast which I was told was cellulitis...it ruptured and has been draining for several days now, and where the main site of the drainage has been occurring is now a hole a little smaller in diameter than a pencil eraser. I have been taking Keflex (I believe that's the name of it) and only have 2 more days worth of doses to finish. Does this mean I'm not responding to the anti-biotics?