I'm dehydrated. When should I go to the hospital?

I’m 8 wks pregnant and unable to hold anything down…water, ice, jello, popsickles they all come back up with-in minutes of consumption. My ob/gyn sent me to the hosp 5 days ago for IV fluids. My situation has not changed at all since then. I have dark concentrated urine, headache, nausea/vomiting, fatigue, rapid heart rate & weight loss (about 7 lbs in 7 days). Since it’s a holiday weekend I’m hesitant to contact my ob/gyn. Should I wait 2 more days until my doc is back in the office, call the oncall doc, or just go straight to ER (cringing at the thought)?