Yes you should be very concerned if you are having that much pain on your right side under your ribs. There could be many problems one of them including a broken rib. It could also be your appendix and if your appendix ruptures you will need to be at a hospital quick.
Any problems breathing? Did you do an activity that may have bruised the bone? This may also be constipation pains, menstrual cramps, gas, or basic indigestion. If problem persists, seek professional advise.
The pain that you are describing can be either due to a fractured rib or pleural friction and lastly due to liver pathology because larger right lobe of liver is on right side. Do PA x ray of chest  liver sonography  liver biopsy as last alternative.