Lump in chest but i'm not sure if its a cyst or not, 2 inches below clavicle.it sometimes disappears a little. i mean its hard to recognize at times. ?

Some possibilities: Could be an enlarged gland, which in turn could be related to infection or cancer; cancerous gland enlargement (in general) tends to grow more slowly and be less painful than infection-related gland enlargement. Could also be a localized fatty tumor, and could be many other things. Best to see MD, and take pics of the lump at times when it looks different; bring pics with you.