I got in the shower yesterday morning and noticed a small lump on my chest, I put it down to a spot at first, until I tried to pop it (I know youre not meant to but its hard), and nothing came out, no pus and theres not even a head. Its quite firm and about a cm in size. Ive read about blind pimples but Ive also read theyre not common on the chest so Im quite confused. Its painful to touch, and is also throbbing slightly,but Ive put the throbbing down to trying to pop it or bring it to a head all morning. Ive put benzoyl peroxide on, is there anything else I can do? Its not even noticable,just a bit red. Im just worried its something else.