I'm an admin at a power plant.
It's a GREAT company to work for and my job is fairly non-stress as far as admin work goes. I get 6 weeks paid maternity leave (comes out of my banked sick time); any time off other than that comes out of vacation but I've been here nearly 20 years and have a good bit of vacation coming to me. So, I may take some extra time off ... we'll see.
With both my previous pregnancies I said I'd work up until I went into labor. Yeah, that didn't happen. I worked until 39 weeks, and both were overdue (one by 4 days, the other by a full week!). I really, really want to do it this time, though. My last labor was really quick; it'd be funny to me to go into labor at work and freak everybody out.