When I take my inhaler I always get phlegm? (Im asthmatic)?

Is this meant to happen? I am asthmatic and use a blue inhaler. I usually get weazy and find it hard to draw breath after when I do lots of excercise. I then take my inhaler and plegm comes up to my mouth, if I swallow it I remain weazy however if I spit it out I can breathe normally again? The only way I can get the phlegm up is by using the inhaler, otherwise I have to wait for it to get better.