Why Are My Tonsils Turning White After Being Diagnosed For Tonsillitis?

Hey, I went to my doctor who diagnosed me with tonsilitus. But since I went there (yesterday) my tonsils have gotten more white with bacteria stuff and even have a few blood blister like things on them. My tonsils have on the plus side gotten smaller. But should I go back or wait for the antibiotics to work first? I have been on penicillin for 28 hours now.