I'm running out of rubber bands for my braces, and i'm going to the orthodontist for about 5 days. can my bite change by this?

Braces: I'm sure you can pick up some rubber bands from your orthodontist or a friend. I wouldn't wait 5 days. All the best.

Don't wait: The rubber bands are for a purpose and help exert forces to either hold the teeth in place or help move them. I would not wait too long to replenish the supplies of te the rubber bands. call your orthodontist/dentist asap

Next time: Next time call before you run out so that the Orthodontist can mail you more elastics. You should be OK, but if you have a chance stop by the Orthodontist's office and pick up some more.

Probably not: It shouldn't matter for that short period of time. If you are running low on orthodontic bands, your first stop should be your orthodontist. S/he will usually have a ready supply, and you can get them for free anytime.