2 yr old still sick after antibiotics

my 2 yr old spiked a temp late last Wed. night. He had a temp all day Thurs. so I called the Dr and got him in Friday. Dr said his throat was swollen but he tested negative for strep. Dr still thought it was strep and put him on antibiotics. he has been on the antibiotics for 4 days now tomorrow is his last dose. and he has still had a fever everyday. he also has not ate but maybe a bite or two here and there. he is still drinking fluids. As long as I keep the fever away with tylenol/ibprophen he will play and acts pretty normal. Do I call the Dr tomorrow or just wait a few days. Ive never had one of my kids still be sick after the antibiotics.