How much will a belly button and/or nipple piercing hurt in comparison to my other piercings?

If your Monroe was a 7 I would really advise against getting your nipples pierced. I handle pain really well (wouldn't rate any of my other piercings higher than a 1 or 2) and my nipple piercings were extremely painful. If you go to a shop that has multiple piercers its a little better because they can do them both at once so it's over faster. But yeah, it hurts alot. I've heard of people who have passed out from the pain of nipple piercings.