Both of your cases are rescheduled with a wee bit of notice but for those who get cancelled really last minute, like after you've already left for or arrived at the hospital, I personally thank you.
I was the emergency my first surgery and after being in CICU five days, I was finally deemed well enough to survive the surgery and they wanted me done immediately. I bumped into someone else's spot and felt awful for that person but truly was too sick to really understand what that person was suffereing.
My second surgery, the last few days prior to my scheduled date, I kept thinking karma would knock on my door and my surgery (same hospital and same surgeon) would be bumped for an emergent case that was currently in CICU. Until I was actually wheeled into the OR, I was sure I would be bumped but thankfully was not.
I did get to know the feeling of worrying about having my date delayed and really, really feel for you. It's very hard but it helps to believe there is a time and a reason and it just was not the right date/time for your surgery. While hard, the right time is worth waiting for.
All best wishes.