Hard lump/bump above right breast but below collar bone. also have pain on upper right arm. what could it be?

Be seen: I definitely would not hesitate to be seen. In that area, the most common cause would likely be a swollen lymph node, which can often come before or after a febrile illness. Although it would be unusual in your age group, I would not hesitate to be seen by a general surgeon if it does not resolve to make sure it is not a neoplastic process.