Gosh, Micah, that label would certainly make me suspicious!
My first thought, however, was something solid that may be seeking a way out of your body.
Have you ever heard of a piece of glass, or metal, wandering through a person's body?
Yet, I don't know if an event like that would make a person ill.
A nine-year-old boy I knew, had a terrible ache in his heel. Doctor x-rayed it and found a half a needle stuck in the side of a bone, completely healed over.
One person who ate an exceptionally good algae, reported that tiny white fibers of asbestos exited the skin of his arms. He had once worked with asbestos in industry.
Of course, I don't think that illness was a factor in either of these cases.
Just a guess, I'm afraid.
I once had a boil on the inner side of my knee, and I knew a girl who had a bad one on the outer side. ...But those were both in childhood.
Maybe grit your teeth and get an ultra-sound, or an x-ray? Sometimes they do x-rays for you at an Emergency facility.
You wouldn't, of course, be the first or last patient with no doctor to refer to. Family doctors are far too expensive for many people.