Hi
Welcome to the forum!
It is difficult to comment without examination. Lump behind the ear could be an abscess, folliculitis (hair follicle infection), lipoma (localized collection of fat), a cyst, an inflamed lymph node or a neurofibroma (localized harmless swelling in of nerve and connective tissue).
I agree with ladeanjanel that you should get this professionally examined by a doctor and not attempt to do something yourself. If it is a cyst your popping it could infect it.
Hope this helps. Please let me know if there is any thing else and do keep me posted. Take care!
I had the same thing, only mine was just below the left corner of my mouth. I couldn't get mine to pop either and after a while, just gave up on it and left it alone. It kept growing so I eventually asked the doctor about it. It turned out to be a benign cyst. My advice is make an appt and check with your doc. Chances are it's nothing to worry about but if it is a cyst, it will have to be removed by a professional.