Size does not matter at all.
look it up most girls actually would choose smaller over large
and do not let penis size bother you its nothing to worry about at age 12 trust me..
in 8 years you will be alot bigger
so hang in there
your still growing your body will change alot more then it is already, a good site i think you should look at is teenwire.com it will help answer some of your ?'s, and please remember dont be the type of guy who is concerned with the size of his penis SIZE ISNT EVERYTHING!