I've been using whitening toothpaste with braces, is this bad?

Not good: You'll whiten the area around the brace, but not the area behind the brace, so when brad's come off it will look like you have a slightly darker patch in the middle of each tooth. Talk to your general dentist about whitening after your braces come off.

Would not: while most whitening toothpaste is very mild, you may cause a shade difference between the exposed tooth and the part covered by the braces. I would wait until after the braces come off and ask your orthodontist about using your retainer as a tray to employ professional grade whitening (we sell this for only an extra $25 after braces)