Well, when i was pregnant i had a very simular thing... my bub would always kick me on the right side just under my rib!...it was his favourtite place to kick me!...I was always very sore and brused and it use to hurt real bad. i could even press on it and it would hurt like you say yours does...

My guess is try and see if that is maybe where your baby has fun in kicking you. If not and your still concerned it wouldnt hurt to tell your doc at your next anitnal visit.