I heard that once you can twist your belly bar, you can change it because its healed but I've only had mine about 3weeks and I can twist it and everything, so does this mean I can change it?

I would advise that you wait a little bit longer, maybe 2 more weeks, because it can be very painful to change a belly button ring when you've only had it a while

Okaay thaanks ut after 3 weeks its totally fine to change yeaah?

No, minimum time before changing a belly bar is around 6-12 weeks. The full healing time of a naval piercing is 6 months-1 year. If you're so desperate to get it changed at least go back to the piercer, at least it'll be sterile and they can advise you on whether you should change it now or later. Also, twisting it is not advised, it slows down the healing process and just creates more and more scar tissue.

Have your piercer check it.