I've Had A Cough For Around Around A Week. It

I've had a cough for around around a week. It started off not too bad, but proceeded to get worse. Last night I started to get a pain around my left rib cage area when I would cough, but now it's really really bad especially when I cough. It hurts to breath in and it hurts to move, what is wrong with me?? Do I need to go to the doctors??