My 1 year old has been sick for 2 weeks and on an antibiotic for an ear infection for 3 days and has just now started getting fevers over 102. why?

Call your doc: Shouldn't be getting fevers from ear infection 3 days after antibiotics if they're the right antibiotics at the right dose. You should call your doctor about it. Without more info (any other symptoms, ear or nasal drainage, sinus pressure, nausea, vomiting, rash, etc) and without examining your child, it's impossible to say exactly what's going on, but it's possible you need different antibiotics.