Why wont why left pinky toe stop twitching?

[Mr Smiley]

I have this twitch in my left pinky toe and it will not go away. Iv had it for almost 3 weeks now and it's really freaking me out. I started running a good bit about a month ago. Do you think it could from that? It seems to start when I relax my leg and its very annoying when Im trying to sleep. What are some causes of twitching? Should I be worried? Should I go to the doctor?

 

[Boo Boo]

cut it off