So, since few months, i have observed that, on the bony protrusion behind our ear(mastoid process i suppose), on the right side of my head, when I palpate the protruding bone with a single finger, i feel there to be some kind of mass which feels rubbery, movable and a size of a single yellow dal/lentil. It doesn't pain or anything, but I am generally worried if that is something sinister. I am attaching a drawn image to pinpoint exact location, it cannot be seem superficially unless I palpate it/no lump i meant. Can this be a lymph node? I want to get it checked by a doctor, but due to me not being able to register with NHS(as i am in Uk), not able to get an appointment. Please guide me. This makes me anxious sometimes. Thank you!