Is my Ankle Broken or Sprained?

i twisted it backwards and fell on my ankle while working and it hurts to walk on it, but its not excrutiatingly painful, i walked all the way home on it ( 1 Mile), and i can turn my ankle every way like I normally can, and without pain. Its not swollen or anything and I would like to know if you think its broken or sprained. Ive had my ankle sprained before and I use a brace which i have on now. It happend 6/29/2011 and i need to know if i should be worried and / or go to the hospital.