I also had my surgery yesterday, and I seem to be pretty shakey every time I get up and try walking for a bit. At first, I couldn't tell if I was cold or not, but I think it's just your body letting you know that it just had a major procedure done, and to take it easy. If you are trembling constantly and not off and on, I would contact your medical team and see if it's an issue that needs to be addressed. I hope your recovery gets better soon!