Better to get it checked out than worry about it. Some chronic conditions can be treated very well these days. Asthma doesn't always "sound" like wheezing, by the way, my family (asthmatics all to some degree) used to refer to it as the boa constrictor, because it feels like someone is squeezing your ribs so you can't breathe right.

A quick trip to your doctor, after writing down when it happens most and what it feels like, is in order. It's not panic attacks, is it?