I agree. BMI is the biggest load of crap ever. It provides absolutely no indication as to how healthy an individual might be.
Why are you so concerned with your body fat percentage? You can get it tested if you like, but I really don't see what you are panicking about. Like DeX says, it is far more important how you feel about yourself and how you look in the mirror. If you look at yourself and are happy with what you see then what difference does it make what your body fat percentage is? If you are in good physical shape and eat right you have nothing to be worried about. Body fat percentage is determined by a large number of factors including sex (women usually have a higher percentage than men), diet (obvious), genetic factors (sometimes it's not something that's completely under your control), and exercise (again, obvious).
It sounds like you're in pretty good shape and you seem to have been previously confident with your physical status because it seems like you all of the sudden started worrying about body fat percentage. Seems to me like you're getting worked up over nothing. Give yourself a break and forget about your body fat percentage and concentrate on how you look and feel.