My 13 year old son throat swab was positive for strep throat infection. He has been feeling symptoms for 8 days, been on Penecillin for 2 full days and tonight he is still febrile 38.3 C, constant throat pain, terrible breath, coated tounge, white patch on right side of throat, headache, fatigue, nausea and dull gradual left abdominal pain, worse with palpation. I am wondering if he needs to be on different antibiotics because after 2 days, shouldn t he be feeling better?