I would say it's normal if coughing quite a lot. I think you actually bruise the tissues around the ribs. It happens to me as well. If it's severe pain then your best bet is to go to your Dr. to make sure.
Pain in the ribs is normal if you are experiencing several days of hard coughing. The muscles between the ribs become strained and begin to ache. It is the same as if you ran a mile your leg muscles would then hurt. You can take over the counter pain medication for the pain.