If it doesn't hurt it might be a cyst.
could be a pimple that is under the skin. Does it hurt? I mean it won't hurt right away but it could just be puss or something that you might need to drain by poking it with a pin. Before you do anything maybe see a doctor, but most of the time it's just ingrown hair or under the skin pimple. around the ear is common for that to happen.
Maybe it's a keloid. They tend to appear out of nowhere. Does it hurt or itch or burn? Have you tried putting any creams or ointments on it?