Possible impending labor?

Any ladies have frequent bowl movements before labor began? These past several days, about 4 maybe, I feel like I constantly have to go. My diet nor appetite has changed. They've been normal (no constipation or diarrhea) until a little bit ago it hit me out of no where and I had to run to the bathroom. I thought I read somewhere that some women experience this before labor. Their bodies cleaning out or something. If this happened to you, how soon after did labor/contractions start?