Have a small little bump on back of right shoulder. it's been there for about two weeks. doesn't hurt to the touch, and hasn't really grown, sometimes it may shrink but never leaves? it also feels like something is inside?

There are many possibilities as to what this could be-it could be a small cyst, a blister, etc. You would need to have it looked at by a doctor to find out what it is and then, once a diagnosis is made, treatment can be given. You can start with your primary care doctor and see if he/she can tell you what it is. If not, see a dermatologist. Good luck!