Hi. My Son Had A Fle Shot Yesterday. He Came

Hi. My son had a fle shot yesterday. He came down with a fever last night at7:30pm and I gave 7.5 ml of ibuprofen. He woke up at 1:30am with a 103.5 fever and I gave another 7.5 ml of ibuprofen . I just realized it's only been 6 hrs since last ibuprofen dose and package says every 8 hrs. What should I do?