It sounds like one a benign skin condition that you can see you doctor for if it doesn’t fade after a week. From the way it’s sounding, it should resolve in its own. If it doesn’t a round of antibiotics will take care of it. It’s very similar to a pimple on your face. As long as it’s tender to the touch, that seems like what your dealing with. If pus oozes out and it’s a white or yellow pus, it’s Chlamydia. Best of luck!