First time mommy here due in January :) I've noticed that if I get too caught up in my day and forget to snack on something I suddenly get nauseated. What I've done is figured out the last thing I was hungry for and smelled it before eating it. Nausea seems to make it hard to convince myself to eat anything but I can only eat after I've smelled the food. I had my husband cook me some beef stew from a can and I smelled the can while he cooked and I was able to eat just fine. Even if it's crackers, try settling your stomach with appetizing smells.