Is it all in my mind?

So today I worked a 10 hour shift, I snacked on chips and pretzels and ate a huge slice of pizza. Towards the end of my shift I started to feel nauseous, and everytime I bend it'll be worst. I'm in my TWW, I don't know if it may be something I ate, symptoms, or just all in my head.. I'm holding off taking a hpt until I get a missed period..