Adding that just makes you sound more immature, honestly.
"I find it easy to maintain abstinence, although at times, i do have my urges"
You're also fourteen, apparently. It`s not that difficult when you`re only fourteen.
"The only way you can get an STD is from intercourse or blood transfusion."
Not just intercourse. Do you not know there`s other forms of sexual contact? Frottage, oral, anal, mutual masturbation?
Also some can be spread through non-sexual contact; herpes is often spread through kissing (the cause of cold sores).
Pubic lice, which counts as an STD, IS transmitted through bedsheets and clothing.
Also, while I highly doubt this, there's the tiny possibility of an open wound coming in contact with the leftover fluids. I do highly doubt that, but I`m sure there`s a slim slim chance there.