I need to rant and opinions.

So I'm at work right now. I work 50 hours a week and drive 12 hours a week just to and from work. I'm a general manager so it's my job to fill all positions if needed. I get it it's my job. But I am 35 weeks tomorrow and I been having such bad pains that are constant and frequent and stuck doing an open to close then open again tomorrow. I can't just up and leave with no other manager here to run the store because I'm afraid of getting fired before I have this baby but I am in so much pain and don't know what to do. I been drinking water and sitting as much as possible but nothing is happening. My area supervisor (my baby dad) isn't answering his phone so I could have him cover my shift to get looked at because he is still sleeping. Should I call my direct of operations and explain how I feel. I need to be seen. The pain is in my back and my whole belly and hips. I didn't know if a fast we could do anything temporarily til I see my OB just to check the baby or not. Or should I just tell them I'm leaving and risk losing my job? Please help!