How many weeks up till is everyone working or worked??

I have a very physical job. Constantly lifting bending pushing standing walking. By the end of the day I can barley walk my pelvis hurts sooo bad and my back. My feet are swollen. I was wondering when you girls started maternity leave? I think my body is telling me to take it easy soon. Im 34+3. Thinking next week will be my last. I've also already been brown spotting, and today feel so Crampy like I'm going to start my period. I've had contractions on n off all day.