To call or not to call?

An

28 weeks and have have a nasty stomach bug. Vomiting started at 4am yesterday and I've been getting maybe a sip of water here and there to stay down. I chugged half a bottle before I passed out for the night just so I wouldn't have the chance to throw it back up. Woke up this morning to pee and it was hardly any and rusty orange. OB's office opens at 8am, should I call just to see if they want to give me fluids?