38 weeks - to work or not to work?!

I'm 38 weeks and I will be 39 weeks on Sunday. I've had a fairly easy pregnancy honestly. I'm still working, I have a desk job as a marketing director, but I've obviously been getting tired rather quickly. By 3pm my back hurts, I'm exhausted and I'd just rather be home. 
My question is should I keep working or not? I'm tired a lot, I feel overworked sometimes, getting up at 4am to workout and then be at work by 7am is getting tiring. BUT on the other hand I worry I'll quit working and I'll be bored stiff sitting around and waiting on baby.. I'm at such a loss of what to do. Any thoughts or inputs? Anyone been in this situation?