What Causes Ribcage Pain?

hey i have a minor pain in my rib cage, not in my heart .. or lungs i worked out and seem to feel fine.. but the pain is just there then it isnt and the more i think about it the more i seem to make it pulsate, It could be psychological but i did smoke marijuana continuously before I went away on a trip, I went threw withdrawal the first 2 days away and the third day had a gained my appetite back. after 7 days off weed .. i had felt refreshed but still had a erg to smoke .. I feel that this may be signs of anxiety because when i smoke, then think about what im doing to my body i get depressed and emotional. Its because i haven't had the time of day to think about what i was doing before my trip to cuba ,,, but being sober really made me think about things. could this be my problem. Thank you, vince