Sharp pain in my back

Cl

Has anyone had back contractions? What did they feel like for you? I'm having sharp pain on the right side of my back and it doesn't seem to follow a pattern but it's becoming pretty painful. I occasionally feel pain in my uterus and have had Braxton hicks with the pain but for the most part it's that one part of my back. At one point the pain maid my leg go numb. Any clue as to what this could be? I really don't want to head to the ER.