Either the baby is on a nerve or you in labor most likely the baby is on a nerve depending on how sharp the pain is
http://www.parents.com/pregnancy/my-body/aches-pains/pregnancy-vaginal-pain/ here ya go! I'm not sure how correct it is, but I read the same thing on other websites as well.
No clue :/ I'm having it too. Ill keep you bumped to the top!