spazzing

i got some new tongue jewelries. i'm gonna put a blue acrylic uv reactive ball on the bottom (cuz im worried about my teefs) and then a metal with blue gem ball on top. i've only had my tongue pierced for 3 weeks though, should i be able to change the jewelry yet or should i wait a few more weeks?
bottom top

......maybe i could just change the balls and not the bar. i would like to change the bar as it is a bit long, but i mostly just want to get that acrylic ball on the bottom