There is nothing wrong with starting young, there are many advantages.
My daughter decided to go to West Point the summer before 8th grade.
2012 Cadet, if you haven't already go to this web page:
http://admissions.usma.edu/startyoung.cfm
Sign up for the mailing list. You will get some information occassionally about West Point and a reminder and information for applying for SLS in your Junior year.
You will also get good guidance in picking your classes in high school so you will be prepared for West Point.
Good Luck!