I Have A Big Lump On The Left Side Of

I have a big lump on the left side of my chin. It's hard, I can move it in a circle, and there is a very slight pain when I touch it. I noticed it yesterday morning. I thought it would go away while I was sleeping last night. When I woke up this morning it was still there and also it felt like it got a tad bit bigger than what it was yesterday. I don't know if it is a really big pimple, or if I got rust in the skin while in one of my CTE classes, or if it's something else. I'm only 18 years old and I'm finishing up my last year of high school. Can you please tell me what it mint be cause it's starting to worry me.