My son, a junior, got steamrolled by his school this year. They jammed two APs and two Honors classes into one semester this year--including AP Calculus--and he had a lousy AP Calculus teacher. This is a kid who had 90s in three honors math classes in hs first two years at his HS. Needless to say, his GPA took a hit and he will probably have to re-take calculus at a local college to prepare for college (his HS is small and it has only one AP Calculus teacher, so he cannot avoid her).
It has been a frustrating year for him and I suspect last semester could have killed his chances for USMA or USNA. So, if you plan to take AP classes, my advice would be to make sure that there is no misunderstanding that could arise between you and your school that could result in an overwhelming AP schedule.