toddlers sternum, any advice?

[chubbin]

JJ has a pronounced sternum on the left side of his chest. It is hard to describe, but ill try. If he is laying flat and i run my hand across his chest, the right side is flat and as i get the left side the bone feels hard and raised, like a very small rock hard boob which i can almost cup with my hand.
I am going to take him to see the gp, but i wondered if anyone here can shed light on this. Dh also has this slightly too but i cant see his chest properly for the hair.
Thanks if anyone can help