Pregnant and overworked

Any other pregnant mom's have a non-traditional job that requires more than just 8-5 Monday-Friday? How do you survive?

I work a job where I could be required to stay late any day of the week. I go in at 8am and could have to deal with an emergency and stay til midnight... I never know what a day is going to require. I'm also on call once every 4 days and might be called to come in at 2am. I never know.

I'm doing what I can, but I'm exhausted. Anyone been through similar while pregnant? Any ideas on how to survive the next couple months.