Last day of work - Pregnant

So I have a physically demanding job, working 12 hour rotating days and nights. The nights are the hardest obviously. I’m due Sept 23 and im thinking of making Sept 18th my last day of work. I feel terrible and lazy for doing it but as of now I am physically exhausted everyday and I’m only 36 weeks. With my son, I worked up until I had him but he came two weeks early, thankfully haha. Just looking to see when other moms took their leave? Not exactly looking for women who worked up until delivery. Also I get 6 paid month off, so if I go over due it’s not a huge deal :)