My Son (19 Months) Has Had A Low Grade Fever

My son (19 months) has had a low grade fever (99.5-100.5) for 2 weeks now. He will get up from his nap in the afternoon and will be fine, about an hour later he has a fever, is extremely fussy (for him) will fall asleep for 30-45 minutes and when he wakes up the fever is gone and he is himself again. He is currently on antibiotics for an ear infection that was 10 days ago. Is this something that I should be concerned about or something that will go away on it's own?