Is My Nose Piercing Bump Just A Pimple Or Infected?

Okay, so I got my nose pierced just a little over a month ago and I'm starting to get a little worried. Upon getting it, my piercer had no problems or anything. I didn't bleed and the piercing went in quite nicely. I got a bottle of salt water spray and I used it a lot throughout the day. Now I use it once or twice a day, and give my nose a good 2 or 3 sprays. A couple days ago, I noticed a small bump near my piercing. I didn't really think to much of it. Today, I noticed that it had gotten REALLY big. I move my piercing a lot, cause the end always ends up in the nook of my nose and it hurts. Am I touching it too much? It looks like a pimple, a whitehead. My sister told me it was a pimple and that I need to pop it. But what if it's not. And won't popping irritate it more and possibly hurt me? If it's a pimple, do I pop it? It's really big and noticeable and I starting to feel horrible about this.. I mean what if it is that 'Horrible Bump' everyone goes on about. And I go on thinking it's a pimple and I get scarred tissue, like that 'keloid' thing. I'm just really worried and I have no idea what to do.