Rattling in my chest?? I'm worried please help!!?

I'm 14 and this has been happening for about a month now maybe. At first I thought I was just getting a cold or something but I now know that I'm not. I'm starting to worry though. Everytime I inhale/exhale I feel this rattling/vibrating in my chest. Sometimes there's a slight pain or my chest will feel tightened with it. Sometimes (not sure if it's actually the rattling or what) I'll feel dizzy and I feel like I'm about to fall over and faint. I've also noticed that when I swim, even when I just float, I feel short of breath and I have to get out of the pool. I'm not sure if this is a sign of asthma or what. Should I see a doc??