I have read your question,
Without Physical examination and medical history , concluding anything here would not be correct.
The symptoms you have stated above can be due to various reasons. But in most cases it is not worrisome , the nearest could be Costochondritis
Costochondritis is inflammation of the junctions where the upper ribs join with the cartilage
that holds them to the breastbone or sternum
. The condition causes localized chest wall pain and tenderness that you can reproduce by pushing on the involved cartilage in the front of the rib cage
. Costochondritis is a relatively harmless condition and usually goes away without treatment. The cause is usually unknown. Costochondritis affects females more often than males.
But again let me remind you that without physical examination it is not possible to say it.
Throbbing on the shoulder could also be the radiating pain
due to costochondritis.
For Further advice I would suggest you to consult a general physician nearby immediately.
Wishing you a good health,