I have come across a formula for whitening teeth. It is mixing hydrogen peroxide and baking soda. Though I have braces so I'm woundering if it will have any negative affects?

The most this will do is help with surface stains - you aren't going to get dazzle-white teeth unless you have a bleaching treatment or professional treatment done. It's recommended by some orthos that patients use whitening toothpastes or rinse with peroxide to keep surface stains at bay, as this helps cut down on discoloration when the brackets are removed.

Peroxide and baking soda will not harm your braces, and actually peroxide can be good for cleaning the brackets with a proxy brush to remove any food or debris your toothbrush might have missed. Lots of people say this makes their mouth feel "cleaner".

I'd hold off on any real whitening treatments until your braces are removed - it's best to treat the whole tooth surface evenly and with the brackets in the way you can't do that. Hang in there and when they are removed you can have a dazzle-white and Hollywood-straight smile! :)

Be leary of using too much hydrogen peroxide - it can be carcinogenic.