I’m 39 weeks tomorrow, is it normal to start feeling lightheaded and nauseous?

Decided to take myself to the mall to walk around, I got food at the food court and ate a little bit and as I’m sitting there I got very lightheaded and nauseous ever since. I’ve been feeling that way. Pretty sure I could vomit but I’ve been holding back. Needless to say I didn’t have it in me to walk around anymore.