How bad do nipple piercings hurt??

I'm really debating getting nipple piercings, I've spoken to friends who have had theirs done so I've found a decent piercer to go to but I'm worried about the pain. I've had my septum, belly button, helix and industrial done as well as my ear lobes so I know realistically it shouldn't be too bad since I'm somewhat used to getting pierced but I'm a massive wimp when it comes to pain so I was curious about pain levels and such before I decide to get them or not.