When to stop working?

My manager has been pressuring me to stop working but it's not really feasible right now. I'm 31 weeks and I don't do any hard work. I work mostly short shifts roughly 20 hrs a week. With my first I was a teen and stopped at 5 months to finish school. With my second I worked till 39 weeks and had her at exactly 40 weeks. When did you ladies stop working or when do you plan on stopping?