Small blister on tip of penis

A couple of weeks ago i noticed a small un raised red blister on the tip of my penis. I'm 21 years old , been in a relationship for over a year now and had sex with the same girl too many times to count and this is the first time something like this has happened to me , no itching or swelling , discomfort , nothing like all those other symptoms are describing for anything major , its just chilling , i have not yet seen a doctor , i have been cleaning my penis extra throughly when i am in the shower just to see if it is poor hygene , so far no dramatic change. please give me some advice on what i should do. Thank you

If you can post an image or 2 clearing showing the blister that would be really helpful …