Morning sickness- NOT PREGO

Tara
Hello All, 
This Am I woke up with chills I was shivering very badly and was very very sick to my stomach. Just brushing my teeth made me more nauseous. I normally wake up with chills and shivering but have never felt that sick before. Im not on my period and there is 100% no way I'm pregnant. Please help!! What could this have been?