Im 23 and I found it yesterday and only noticed after shaving close, its not sore at all and feels like a cyst. I also have a cyst on my kneck that i have had since i was younger , My mum said i had a cyst under my arm when i was younger but ive only just noticed it. You can only noticed it when you press it as the same with the one on my kneck , do you think its any thing to worry about or should i just keep an eye on it and make sure it doesnt change size or shape ? I think i irritated it maybe from shaving but its not red or sore and its tiny. Any help would be appreciated.