Should I go to ER?

I'm 23 weeks, having severe abdominal pain with nausea and vomoting and I feel like I have to push or take a giant shit but I can't

I can't call my doctor I don't have access to a phone

I don't know if I should be worried or if I maybe got food poisoning from something I ate or what.

I don't want to wake my roommate up to drive me unless I need to as we live an hour away from the hospital