When should I go on Maternity leave????

Hi I'm a mail lady here in sunny south Florida I'm currently 32 weeks pregnant and doing 9-11 hours a day.  My idea was to go on maternity leave September 1st when I'm 36 weeks but I'm not 100% sure if I can survive until then...... What do you guys think is a good time for me to go on leave?? Maybe at 34 weeks? I'm so undecided