i remember having something similar when i was about 13 or 14, right beffore i started seeing a gyno, i was not about to let my mom know because either she would want to see it or she would have taken me to my male dr at the time, and that wasnt gonna happen lol! it was about the size of a dime and raised, also located on the crease of my leg on the inner thigh. it got so painful i was having trouble walking, so that night i remember cutting it open myself (not recommended) and omg the smell was gut wrenching, but it cleared up, i still have a scar there and can feel a tiny knot but i never had another one.