If you're not keeping even water down you are at risk for dehydration (I you've been vomiting long) I got the flu with my first and after 12 hours of nothing staying down they sent me to ER for fluids.
Try sipping gatoraide or Sprite like a tsp at a time. And if your OB/midwife as an on all service give them a call.
Just be careful of dehydration, so if you think you might be (haven't gone to the bathroom in 8+ hours) go to the ER and make sure they fully hydrate you. You have to use the restroom before they discharge you because you're pregnant. Make sure you remind them you're prego as some ER Dr's don't know you aren't allowed to leave until you pee.