Not be be weird.. But why does it burn down there?!

Could be a yeast infection or a urinary track infection. Can't really tell unless you go to the doctors. Nothing too serious and common among girls. Tell your parents and go to the doctors, and don't be embarrassed! I always say i'd rather be safe then sorry.

You can have tight muscles in your back that are pressing the onto the nerves going to your bladder which will send pains into your bladder and all the way down to your vagina. Many times it's diagnosed as a bladder infection. to get rid of the pain you have to free up your back muscles and here's how to do that:
Back:
(do from a sitting position)
Place your left hand on your left leg next to your body. Place your right hand over your left shoulder, fingers over the back and the palm in the front and firmly pull down on them and hold. After 30 seconds slowly lower your body forward and to the outside of your left leg, keeping your left arm fairly straight as you do. When you reach your lap remain there for another 10 seconds, release the pressure but rest there for another 30 seconds. Then reverse your hand positions and do your right side.
For best results relax your body first by taking a deep breath and exhaling then remain this relaxed.

It could be a bladder infection, or a urinary tract infection. You should probably go to the doctor. Also, drinking cranberry juice will help.