According to the picture below it looks to me like the pain is coming from around the cuboid bone and the 4th and fifth metatarsal towards the cuboid bone.
http://www.foot-advice.co.uk/images/foot_top_view.gif
HOWEVER, I was sat down with my feet under my school desk and suddenly had a sharp pain coming from the area explained above, but I did NOTHING to cause this. I can walk on it but it does cause me pain when doing so and also moving my ankle is extreme pain. The area is quite swollen and is pinkish in colour.

Could my ankle be sprained?