feeling odd..please help!

so it all started on the 19th of dec. i had burger king and while chewing i started to feel kinda nauseous. it didnt taste weird or anything but trying to swallow what was in my mouth made me want to puke. after a few sips of sprite i felt fine and so i continued eating. now its like almost a week later and everytime i begin to eat something after 2 or 3 bites i just feel like im about to throw up at first it was just fast food now its home cooked stuff too. the only things that dont make me feel nauseous while chewing are junk food like chips and soda. even water sometimes makes me feel sick.does anyone else have this problem?? like its not after i finish eating or even the taste of the food, its only while i chew i feel like im gonna be sick...its weird... p.s. i shouldnt be pregnant i just got off my cycle a few days before this..