I heard that belly button piercings hurt really bad and get infected easily. If done right they can look really cute. My 16 year old sister wants to get one but we're all rolling our eyes; she's a bit lazy and probably wouldn't clean it and she complains A LOT about pain.
But, you're not my sister so good luck.
As for myself, I'm not sure if I would get any more piercings. I got my ears pierced about 7 years ago and I really can't imagine myself getting anything else. Defintely not anything crazy like a bull ring or a monroe though. I might get more piercings on my ears though because I think that upper piercings on ears look really awesome.