Ok. Here it goes. Sorry for the wall of text.
I am 16 weeks pregnant, and just starting to get larger than usual. It's not been a difficult pregnancy as such so far, but I've had issues with low blood pressure (including passing out at work) and in recent weeks have developed really agonising sciatica pain in my left leg - although some days it is better than others. The doctor reckons I have a dodgy disk and the baby growing is putting pressure on it and on the nerve, and that the pain is likely to go away when the baby is born. For those counting, that's five months away. Happy times.
I work in retail, and as such spend the majority of the day standing behind a till, fetching and carrying, and occasionally crawling about on the floor looking for things people have dropped. I've been finding it pretty hard going recently, to the point where I've locked myself in a cupboard and cried with the pain. Management have previously promised me a stool to sit on behind the till, so that I can serve and rest up a little at the same time. They did provide me with a stool, but took it away again after about two weeks, saying that they needed it for their office. They have replaced it with a kickstool, which is so low that I can't get off it without assistance if I do sit on it and certainly can't serve customers - I can't see the screen on the till from down there! I can't go and sit elsewhere as we are massively understaffed and I'm often alone on the tills for hours at a time - there'd be a riot. I asked again for the stool today; no-one was in the office and I offered to bring it back as soon as they needed it. I was refused.
So would I be unreasonable to turn up with my very own stool, park myself on it, and get on with my job without being in pain all day? I don't want a row with my mangers, and I know It's pretty passive aggressive, but I'm running out of ideas.