Could this be asthma?

Lately (past year, maybe), have been having a really hard time breahing while I'm running. I wheeze a LOT, cough, have a lot of mucus in my throat, and a little tightness on my chest. When I was younger, I had bronchitis at least four or fivetimes. The problem is I am not super in shape, but I also not very out of shape. I am a competitive swimmer and this breathing has never bothered me in water. But for some reason, when I'm running I can't shake it. Also, I'm slightly overweight. (slightly as in 5-10lbs), but I haven't done any bmi thing and I am quite strong and not actually fat (I don't look overweight, I look average.) so I was wondering if this could be asthma?? I'm 15 by the way. But I know sometimes asthma can show up then. Please help!!!