Should I go?

I'm 21 weeks and havent been able to keep anything down for the last 2 days except some lemonade. I'm having really bad stomach pains, extreme nausea and repetitively vomiting but I don't think I'm that dehydrated so should I wait till it gets worse or go ahead and go in? My medicine just isn't working and I feel absolutely horrible. I haven't gone to the hospital in about a month now because I was on a reglan pump which was working but my stomach was getting to sore to keep poking myself so I stopped using it and the reglan in pill form just isn't helping, if I do go in do I go to labor and delivery since I'm past 20 weeks?