I'm looking for some advice on whether or not what I propose would be considered reasonable by an employer and how to go about asking for it. So here's the background:

I've had all-day sickness from 7 weeks to present (25 weeks). In total I have had about 4-5 weeks off work due to the nausea/vomiting. Once it started to get controlled with medication (Zofran) at about 17 weeks, I've been able to mostly attend work, though each day is a struggle. Over the past week or so I've felt that the nausea has become worse and although I'm not tired really, I've noticed that if I do too much activity/travelling (just to and from work etc), then the nausea gets worse. I'm also concerned about the possible side effects of the Zofran - I have been on it for a long time now!

I have an OB appointment at the hospital tomorrow and I'm thinking of asking him if I should cut back work. I've already planned to start my maternity leave at 34 weeks (the earliest they will let me access maternity leave). I was thinking of asking to work 4 days a week using a day of annual leave each Wednesday.

1. So is this unreasonable or rude to ask for this (my area is already short staffed and very busy)?

2. And also, do you think I should get a Dr's letter or only if my employer asks for one (note: in my company if a Dr or med cert says you are sick you are not allowed to work even if you get better or feel you can ).

And finally, I guess I'm not actually physically incapable of working 5 days a week, it would just be nicer for me to work 4...

Any advice muchly appreciated.