shooting leg pain?

Hi! I have a question for y'all. I'm 37 weeks and the last couple days I've been having a lot of Braxton hicks contractions. Today I've been having a shooting pain down the back of my left leg. It's bad to the point where I have to grab onto something to stay standing. It usually stays there for a few moments before passing. I've tried googling, but haven't had much luck.