Are BMI always correct? I think mines wrong?

[saule]

Im a female, 2 years old, 5'11(sometimes6ft) and 155lb.
I was looking at my bmi because i felt i need to loose weight but when i looked it said that I should weight between 140-170lb.
is bmi correct or incorrect? do i look over weight?
this is a pic from me last summer:
http://img.photobucket.com/albums/v248/saule99/l_7964b8be523f2730232b904595dc63-2.jpg

this is where i got mu bmi chart
http://www.rush.edu/rumc/page-1108048103230.html

 

[Crissy]

youre 2?

you look old for your age