Hi Liz,
Don't know if you read my reply to your other post (Made it one). I had a lot of fluid retention post surgery which was increasing, not decreasing, as the days went by. I discovered it was one of the side effects of the pain meds I was on (pain meds stop a lot in the body, they don't just interfere with digestion/bowel, but also stop lungs clearing, and stop the way fluids are moved around the body, hence they can lead to fluid retention - I got this from doctor). When I stopped the pain meds (too many side effects) the fluid rentention left very quickly, so much so that my blood pressure dropped too low and my sodium levels got too low, yes sodium too low ! My GP took me off the diurectic med (I was instructed to add salt after that !) and fluids got back to normal. That might be something you find happens.
Also I did a lot of walking - it was last January and very wet here in the UK (it rained unusually heavily for about two months causing flooding in our area) and no chance of going out for walks, so I walked up and down the living room ! Walking helps get fluids moving, something to do with stopping fluids pooling in the legs.