Directly below my clavicle on the right side above the breast i have a hard mass. no pain, no other symptoms. what could this be?

See your Doctor:: Needs to be investigated, as it could be from skin tissues, like a sebaceous cyst, a lipoma, ganglion cyst from underlying joints, a fibroma, or from the bone, like an osteoma. Generally these would be painless and hard or tense. Clinical examination, xrays and/or MRI would help in identifying them. Most likely it'll need to be removed and only then a final diagnosis will be made by a pathologist.