DS has had a cough for 2 weeks. He had a fever early Wednesday morning, but it seemed to subside after 1 dose of Motrin. On Thursday morning, his fever returned and he was diagnosed with an ear infection. He has been on antibiotics since then. He's ok 6 hours after Motrin, but then his fever sets in again 7-8 hours after Motrin. He has never had a fever for more than a day. How long should I expect this to last?