About 3 months ago, I've noticed a small blemish on the head of my penis, it then formed alittle red, and went away. It was probably the size of the top of a pen, maybe alittle bigger. It has now returned in the exact same place. when i pull the skin tight, its not noticable, but left alone, it looks like a very small pimple thats just red, nothing white, no discharge or cluster, just the one pimple...I have not had unprotected sex since my last std test, but i have engaged in oral sex a few times. I am very scared that because of it recurring in the very same place, it has to be herpes. This is the second time. I have been stressed recently and from what i've read on this forum, i cant get it out of my mind that its an std, very scared.