It could be a possible infection from shaving. do you change out your razors often? if not then a lot of bacteria grows on the razor and it could have gotten into a little tiny nick/cut and caused a problem, if you're worried and this is still going on i would definitely get looked at. If it is going on over 7 days, i wouldn't take this lightly, despite the embarrassment. they are trained professionals and will not flame you for your worries. don't be so hard on yourself. Take care and hope this get's sorted soon! Sincerely, Elizabeth
I had a similar problem several years ago. I went to the doctor who examined my anus. He said that it looked like a fungus. He gave me medication to apply for several days. The fungus and the itchy feeling went away.