I feel

I constantly feel like I need to eat something my stumic feels empty to the point I feel nauseous like I'm going to throw up ? I just had lunch five hrs ago and now I had two hot dogs and I still feel like this and this Ben happing a lot lately could I be pregnant I just feel hungry all the time and I thought i smeeled something last night and thought it was the heat so I turned it off idk how I could of smeeled it from down stairs because now I smelled it when I can home and two yeaster day I had a head ack all day ?