What Causes Sore And Raised Sternum?

Hi I have had a raised sternum for several weeks which is sore to touch. Its almost like a rib. I also have pain when i stretch back my arm which i think is the muscle and it goes all the way to my back, its near my shoulder blade. I want to the doctor as the dull pain / ache was always there and was unpleasant. The ache is much better but the sternum is still prominent. Should i go back to the doctor?