I had my belly button pierced yesterday and I wondered how long do I have to wait before I can change my belly bar?::)

Everyone heals at a different rate, but as a good rule of thumb, I would wait at least a month. It may look healed on the outside, but the inside takes a while longer. Just make sure you are either cleaning it with H2Ocean or a mixture of sea salt and warm water.
Also DO NOT TURN YOUR JEWELRY, unless you are cleaning it. If you are still unsure, see your piercer when you want it changed.
Your piercer should have told you when it would be OK to change it.
Every piercer may tell you something a little different, also remember that doctors don't really know as much as they let on about body modification.
Sorry to ramble- hope it helps.
KEEP IT CLEAN!

I go to LaBelleVie. My piercer is AMAZING. He's so informative and he has a very steady hand. He's done all of my piercings. Anyway, so I got my belly pierced back when, and after a week, I went back in for him to check it. I don't quite remember, but I believe he had me wait another week or two. I then went in the week after I had him check (so 2 weeks after I pierced it), he had changed out my ring for me. Like the person before me said: it depends on the person. But usually 1-2 weeks generally the piercer would change it out for you. Don't attempt to change it out yourself afterwards. ASK your piercer first.

U can change it without actually taking the bar out if u just change the balls then it will look different but be the same bar it does work