Hello, I was just showering and noticed a small sack/blister thing on the rim of my anus closer to my vagina. For the past two weeks my anus itches off and on. It was not until tonight I felt this thing. I did shave back there about two weeks ago and then thats when the itching started. I figured it was the hair growing back and irritating it and i thought it could also be some underwear I wear bc it seems to itch more when i where thongs or lace underwear that ride up a little more. But now i do not know. I have had unprotected sex but it has been over 2 months. I am very worried it may be something bad and am scared. What do you think it may be? Please help.