My Son Almost 2 Started With A Cough 6 Days

My son almost 2 started with a cough 6 days ago. He got a fever 4 days ago and it spiked as high as 104. He has been on antibiotics for 3 daus ago. He still has a persistent fever ranging from 100 to 102 but mostly closer to 101. He has been sleeping most of the day with not much play just kind of laying around. The cough is the same or worse and he has hardly eaten all day. He also has a congenital heart defect that adds to our concern. Is it normal to still be this sick on an antibiotic?