Elevated temperature? 4wks

Amanda
Hey everyone! I'm about 4weeks and I have a 99.9 fever and feel nauseous. My nausea has calmed down from what it was about 2-3 hours ago but the fever remains. 
Anyone else experience low fever as a symptom or could I be fighting something off? (I'm also extremely tired and have an autoimmune disorder) just trying to rule something's out! Thanks!