I've been like that for about a week now too. Baby is due Saturday! But still no water breakage and the pains are happening irregularly :/
That's actually exactly how my labor began with my first. Those waves of pain that feel like your stomach is cold, or you need to poop, were actually contractions. At the time, I laid down, took a small nap, and when I got up my pants were wet cause my water broke while I was asleep.
You might be at the start of your labor. If the waves of pain/tightness are at regular intervals, go to the hospital when they are about 5-6 mins apart.
Good luck! Hope your labor is easy!