I was a cleaner when I was pregnant and left at 33 weeks with my first. It was getting too much on me. The weight of the equipment, constant long bus rides to get to work, bending in weird spots. It was too much. Cleaning your house is different than cleaning 5 houses in a day and on a time crunch too so it takes its toll. If it's too much and causing contractions, take the rest and the time off, you need it.
I stopped at 36 weeks. It was killing me. Going to hospital tomorrow night to get foley catheter and Wednesday getting potocin.