I'm 17 years old, quite short don't know my height really, weight 7.1stone, am i overweight?

Height/weight: You must have seen your pediatrician regularly as you grow up. That doctor mus have a copy of your height and weight chart.. If you are growing properly that should be very apparent and you can relax. If you are falling below the height or weight chart your doctor needs to find out why and make plans to try and correct things. You can find growth charts on the web and plot where you are.

Hard to say: Since appropriate weight is quantified based on weight/height, without a height, it is not easy to give you an answer.Most consider 5 feet (1.5m) short for a woman and 7.1 stone (99.4 lb) would give you a Body Mass Index of 19.5 which would be considered normal for that height.