Do I have exercise induced asthma?

I've been running for a couple years now and can't seen to better myself at all. I can breathe fine the first minut and then after it goes downhill. I breathe really heavy and feel like I'm going to pass out if I run more than 2 miles. All the other girls on my soccer team start out like me at the beginning of condioning but then do so well by the time season starts. I still loove to run, it's so peaceful, but I just want to enjoy it. And it wouldn't hurt to be as good as the girls on my team. Please help?