FTM.. need some advice..

So, I'm trying to work up until my due date(Oct 5) but the past few days my legs and feet have been swelling to the point they are falling asleep and hurt.. I work anywhere from 6-9 hours standing up to 5 days a week. Should I ask for time off or keep going? Are there any risks? And how do I go about it if I do want to get on leave or something as I've only been at my job for 3 months, and only have state insurance?? Any help is welcome! Thank you!