Belly Button Piercing, Does it Hurt?

Ok, so, I'm 12. I haven't asked my mom yet if I can get it pierced. I REALLY want to. But, I DO NOT have a very high pain tolerance. Except when I'm mad. (I don't know....) Um, so I was wondering a couple of things: How to persuade my mom to get it pierced? How to either cope with the pain or how to numb it before hand? Thanks!