I was diagnosed with cellulitis 5 days ago on the side of my right knee and it wrapped around behind the knee. They prescribed Bactrim DS 2X a day. I did not have any pain, blisters, or much swelling. Today (my 5th day) the area of infection is still growing bigger, but seems lighter in color, less heat, and the area is flatter. Should I give it a couple more days before seeing the doctor? Does it sometimes still spread before it loses the battle to Bactrim ?