It's near my hairline, on the right side. It's probably m&m or a pea sized. It's been here for 5ish days (happened after a haircut?) not sure if I should go to a doctor or should I even be worried? I've done some research and it seems to be a lymph node, which is some sign of cancer (which has always been my biggest fear of getting) not sure what to do or if it's even harmful, i've also read that lymph nodes fight off infections or some sort like that.

Any help is appreciated.