I (and my doctor) was convinced my chest pain and breathing difficulty last year was exercise induced asthma. I was taking the inhalers, etc. for it and it helped - just a little. Of course it turned out to be something much more serious than asthma.

I'm glad you're getting all the scans, etc. Definitely tell your doctors about this and ask them what they think about this new symptom. However, from what I understand, adult onset asthma is apparently not very common - especially if you've never before had symptoms. Once I was finally diagnosed, etc., I was talking with a doctor friend who specializes in all this sort of thing, pulomonolgy/allergy (he lives in NYC or I would have gone to him originally - and I don't generally like to bother my doctor friends with my "stuff" - my friends don't generally bring their law "stuff" to me.) Anyway, he told me that it is apparently quite unusual for someone with no previous asthma to suddenly come down with it, exercise induced or not.

You may also was to be checked for allergies - maybe there's something "blooming" this time of year that set you off. Or you might have a chest cold.