Weird pains at 36 weeks

Okay so on and off since last night I've been having some strange pains. I don't want to go to the hospital over nothing but I want to know what some of you think. So, for one tmi I've been having frequent bowel movements...not diarrhea but definitely much more frequent than normal. Then I kee having this pain that's in my back at first and feels like extreme gas pain and then my stomach feels like it's in knots (again like extreme gas pain or like you're about to have severe diarrhea). Sometimes they're so bad I'm doubled over. They seem too painful to be Braxton hicks but I haven't really noticed a pattern or anything...