HELP!!

Sky

So I started this job for Evs at the hospital April 11th it’s only been a little over a month I’m trying to stick it out to get pass my 90days but it’s very physical and draining I’m super exhausted and most times I over heat with having to run around the entire hospital cleaning .. I’m currently 28 weeks and they are working me like a dog I was only supposed to be on the schedule weekends but now they have my with literally like 1 or 2 days off .. I don’t mind working but being pregnant while doing it is a lot .. I really want to ask them if I can postpone my employment until after I have the baby and I’m physically able to do the work but I’m not sure if that’s even a thing u can do ??!! I need help and I don’t want to just quit please help I need suggestions!!!