It took a couple of days for mine to fully adjust. When I first got mine in they hurt like fuck, I had to take some pain killers it was that bad. You'll get used to them quickly after that, you forget they're even there.
Just make sure you get the wires at the end trimmed properly, or they cut big trenches into your cheeks. Everyday when I feel the insides of my cheeks, I feel the scars left by my braces. How can I ever forget that I had braces now?