I've been tested thoroughly for asthma&i don't have it.@bball after running only 5 minutes i started wheezing, short of breath&cudnt breath.not first time?

Many poss causes: There are many causes for exertion related shortness of breath. In fact some types of asthma are mostly triggered by exercise (exercise induced asthma) and this can be hard to diagnose, it may need pulmonary function testing before & after exercise for example. Still asthma is not the only cause and other heart or lung, problems are possible, or even anxiety issues. Best to talk with your doctor.

Exercise asthma?: If you test only included spirometry without a challenge (rapid exercise) something may have been missed. Could there be other issues working (ie out of shape, anemia, overweight, etc.)? Sometimes it is a matter of excluding all possibilities before coming to a conclusion.

? Vocal cords ?: Some people have these sudden events due to an abnormal spasm within the vocal cords, which restrict the air flow and mimic an asthma event. This can be evaluated and confirmed by an ENT. Treatment utilizes the skills of a speech & language pathologist to teach you how to breathe thru the events.