If it comes and goes quick it is Brenton hicks if it doesn't go away quick it might be because the baby favors one side more then other and that puts a lot of pressure on the mussels. I just learned that from my doctor couple weeks ago because I had crazy cramps in the same spot. I hope it helps. If you really worried about it you should call your doctor in the morning just for piece of mind
If it comes and goes quick it is Brenton hicks if it doesn't go away quick it might be because the baby favors one side more then other and that puts a lot of pressure on the mussels. I just learned that from my doctor couple weeks ago because I had crazy cramps in the same spot. I hope it helps. If you really worried about it you should call your doctor in the morning just for piece of mind