I'm on day 5, LPN, and I think I know what you mean. I've been living in a bubble for 5 days now...it's surreal. I think I'm working the pickles out of my brain. Maybe yours were just in your stomach. Maybe it's the stress or nerves of multiple changes. It's funny that you have that sense in the pit of your stomach and interpret it as trouble; I get the same thing when trouble is near. But, I'd consider this one an anomoly of change. If you think it's an ulcer, you should see your doctor.