At what point do you decide to go to L&D? I've been having cramps on and off in a timely manner for…

At what point do you decide to go to L&D? I've been having cramps on and off in a timely manner for about an hour or so now. It's not unbearable pain but uncomfortable. It's not Braxton Hicks because I know what those feel like, this is an all over lower belly cramp especially when I walk. I'll be 31 weeks tomorrow. Just didn't know if it was anything worth going to the hospital for or just let it go?