Prodromal labor or what..

Twice I've given birth before, and twice I went into L&D; for reasons other than contractions (1st time water broke, 2nd I began bleeding heavy, menstrual type blood).

I've never gone before 40 weeks but now at 38+6 I'm nauseous, crampy, having diarrhea (sorry tmi),& up all night, every night with contractions that are very irregular, but painful.

I feel like I'm starting labor, but because there's no contractions (during the day, at least) or obvious signs like my water leaking, I have no idea if I should go call my dr or not.

I have two other kids and don't really want to be sent into L&D; to be monitored for no reason.