2 year old 103 temperatures?

My daughter Kendall has woken up every morning for the past 4 days with 103 temperature. By noon it's gone and then it comes back throughout the day for 10 minutes at a time. She's miserable when she has a fever but when she doesn't she's fine! The pediatrician said they don't know whats causing it and couldn't prescribe any medicine, but said if it continues for another week she's going to need tests done. Has this ever happened to anyone else....?