Nausea

I didn't have nausea at all in the beginning of my pregnancy, and just recently, since I got to 11 weeks, i've had bad nausea. Like, I was doing the dishes after making chili, and I almost threw up all over the sink seeing and smelling the meat, and today I just went to Denny's for dinner, and I got home after my stomach wasn't feeling right, and had to swallow down vomit. I know nausea is normal, but is it supposed to do a 180 like that? I feel like i've become so sensitive to smells and stuff now