I have this red lump on my penis head. I'm getting to worried. What could it be?

I'm 18 years old. I noticed this single red lump on my penis head three weeks ago. It is not itchy but it seems to get bigger. I have not experience any sex with other person in my entire life. I have no partner. But I do masturbate almost once a day. I do have a proper hygiene and I wash my penis with water and soap after I cum. Or else, I clean it with clean handkerchief. That's all I remember. I don't know what's the cause of this.

No doctor answers yet