B.K.
I had a nauseous stomach yesterday as well. It happens occasionally, and for me, is caused by anxiety/high stomach acids. This is a common problem.
I like you however, dread the stomach virus/food poisioning, so it is easy to go into worry mode.
It has gotten easier for me with time and progress, but stomach issues...even IBS symptoms which I should be used to by now, are a trigger for worry.
I do feel that reading this book helped, and I am going to post the link, as I have for others here. I really recommend it. (it even has a specific section on for 'emets')
http://www.amazon.com/Overcoming-Health-Anxiety-David-Veale/dp/1845298241
I hope that all goes well with the party! I know it will be great...and a good time had by all.:)
Give the birthday boy high fives from us.
S.C.