Hi!
How scary for you to go all weekend before knowing what that is!
Obviously, you will keep a watch of it all weekend. If it goes away, it probably is a lymphnode, which I hear is very common especially in cold & flu season.
If I were you, I would have it checked out for sure. Just "feel it" really good and make sure you have an excellent description of it in case it disappears before the appointment. I would even try to "size it" if you can, with a marble, or ball or something.
I hope everything goes OK for him. I'll say a prayer for you guys this weekend.
~N. :O)