it’s unlikely that you are pregnant. But if you can’t be safe, don’t have sex. Get on hormonal BC, require him to use condoms, etc. If you’re worried about semen on your hand getting you pregnant, you’re clearly not informed enough to be having sex.
Reach out to any free clinics or planned parenthood, or go to a primary care doctor before you become a teen parent who has to make that ridiculously hard choice between keeping it or abortion.