Rib pain?

Brenda • 25 and just had my princess.. Briseis is almost 4 months :)
I'm 27 weeks pregnant and since last week I started feeling rib/lung pain. It got so intense I couldn't breathe... If I cough my back, where my ribs/lungs are, hurts a lot. I have asthma and I don't know if this is normal I did use my inhaler when breathing became very difficult but was it an asthma attack? Does this happen during pregnancy? It's my first I have no experience and this is really hurting me :( 
Please help!