Ok, so I'm a 13 year old girl, okay? And I have had periods ( probably not an issue ) and recently, I got a Very high fever, 104.3 Fahrenheit to be exact. And This kind of high fever happened last October too. My Mother had taken me to the ER and they said that I had 'Upper Respiratory infection ' but I definitely know that's not the case now. I had taken 2 Alka-seltzer Cold and cough medicine ( purple clear large pill ) and that had brought my fever to 100.2 Fahrenheit but then about the next day, my fever rose back up to 103.4 Fahrenheit. I can't seem to sweat this fever out and I've had symptoms of Fatigue, chills, sweating ( not a lot ) nausea ( but no vomiting ), pounding headaches, body aches and weakness. I am also trying to hydrate a lot. So, what could possibly be wrong with me?