Is my belly button piercing infected?

i got it done on April 22, 2011 and i though it was healing. but then i took a bath and it started to show signs of infection. i did the salt soak thing and it worked but then it fell out during basketball practice about 3 weeks ago and i had to push it back in because it close up a little. ever sense then it has been hurting, it pusses sometimes but very little puss comes out and it doesn't happen very often. why does it still hurt?