Also I just noticed earlier on in this thread you were asking about being made to sit up in a chair the day after surgery and the pain: they will get you moving as soon as possible. Staying very still lying in bed for a long time is bad for you in many ways - you risk pressure sores (bed sores), blood clots, and muscle wastage, and in general it's good to move, just as it's good for healthy people to exercise.
That said, you'll not be in a healthy state, and the amount of movement you do should reflect what's best for you as an individual at each stage of recovery. If you feel worse than predicted (of course hopefully this shouldn't happen), you may be advised to wait longer before getting out of bed. I've had surgeries when I was up and walking the same day, but my most recent surgery a few days ago I didn't get out of bed for days (this was an emergency surgery - nothing like what you're having). In this situation they will do things to keep patients as healthy as possible without moving them - changing their position in bed to prevent sores, giving medications to prevent blood clots.
Some people seem to need nurses to encourage them to get up and moving, because it can be very hard to do so when you're in pain and feeling ill. I tend to know myself when I'm ready. I push myself to get up and moving, once I feel able to.
So let the nurses guide you as to when you should get out of bed, how long you should sit up for, how far you should walk, etc., but let them know if you feel like it's too much, or if you feel you're ready to do more.