IMO, getting your nose [re]pierced is no big deal, unless your job would frown upon it. But you can always take it out. That's the beauty of piercings.

When I was in college I had my friend pierce my eyebrow with a needle or a safety pin (can't remember which). A year or so later (still in college) I got my nipples pierced (at a legit place) -- while tripping on acid.

So, you could totally be making a way more extreme decision. But that's just my opinion. I know I'm kind of playing devil's advocate, but I happen to be a fan of piercings.

Anyway, maybe just think about it for a little while and see if your mind changes. You already mentioned you were thinking about it -- you didn't go out and get it done at your first impulses. So that already shows self-control. I can understand why you'd be mad.