stop working

Okay so, I work a job where I am on my feet 100% of the time. I'm constantly lifting things and bending. The bending is the most challenging for me and my feet do get sore, some days more than others. I'm 7 months pregnant now and due May 18. Not super big but big enough for people to notice. I don't have a lot of money, but luckily I was able to get pretty much everything the baby will need other than diapers and wipes. I've been getting a lot of hours lately, and have began to wonder when I should stop working. The last thing I want to happen is to go in labor at work. Only problem is that I will have no income what so ever, I'm not eligible for any benefits. My s/o has a low income as is and he would be supporting me. I want to work as long as I can to earn money and maybe begin saving. But I absolutely do not want to risk going into labor at work. Can I get some opinions?