maternity leave/ short term disability?

Maibis
Hi everyone, I'm 27 weeks with twins and a preschool teacher. I spend all day on my feet, bending over and sitting on little chairs, I get out of breath so fast and bc of the bending or extra weight, I feel pain in my lower back and knees, I feel like I can't take work anymore. Has anyone been put out of work this early? Or what was the earliest you were put out?