What Causes Recurring Fever In A Kid After Recovering From Ear Infection?

My son is 15 months old. He had an ear infection 2 weeks ago and was treated with antibiotics. He seemed fine but he woke up with a fever 102.1 I gave him some Motrin and took his temp about 30 mins later and his temp is going down. We are at 101.3. Is his ear infection back?? Or could he be teething again?