I Have Suddenly Developed A Sharp Pain In One Lung

I have suddenly developed a sharp pain in one lung that gets worse when I breathe in deeply. I just got over what I consider a mild cold, or I still have it though it's not as bad. The cold started last Friday. I think I may have pleurisy. If I do, should I see a doctor? Also, is it possible for me to be contagious (I'm an elementary teacher)?