Re: If i were to...
STD's can only come from other people. If you have the herpes virus, you can transfer it to other places on your virus, but you had the virus anyway.
STD's only come from infected seminal or vaginal fluid or other bodily fluids. Unless you've come into contact with said fluids, you're okay. (If yours is infected, you already have the infection.)
STD's can only come from another person. You can be born with them, if your mother had them, but in that case they would have been found by your doctor a long time ago.
So the simple anser is: YOU CANNOT GET AN STD FROM YOURSELF.
Also, this question has been answered in the guide. Please read it before you post.