Belly button piercing?

I've had my belly button pierced since March and I was told I could now change it. I have the same ring I got pierced with in now, and today I went to take it out and clean the bottom of it and change the little ball at the top. When I tried putting it back in it was hard to get in and it started bleeding and hurting. My piercing also looks a little crooked so maybe that has something to do with me having trouble putting it back in? But I changed it a few times before and never had this problem. It doesn't show any sign of infection nor does it hurt. Is there anything I can do to fix this or did anyone else experience the same thing?