Are you going into a physical workplace?
At 36 weeks I’d get a doctor’s note to at least get a more ergonomic chair if there’s money/capacity for that sort of thing, and request home working as a reasonable adjustment if it’s viable in your role tbh.
Obviously the above might not be feasible dependent on industry/role, but if it is- exercise whatever rights you have, and be as comfortable as possible in these last few weeks.
In my first pregnancy I was adamant to not ‘take the piss’ and soldiered on at all costs- and still got royally shafted by a ‘family friendly employer’ (diff industry to where I am now). Should have looked out for number 1 (and bebe) a little more