Will my brace hurt that i am getting? It is like a spring, it goes near the roof of my mouth?!?

I am getting a brace in about a week, and I want to know if it is going to hurt the brace looks like a spring on the picture I saw and it goes along the roof of your mouth, it starts small then gets bigger towards the middle then smaller again! I really want to know if it will hurt, if you can tell me anything please help. Thanks, Rosie x