Labor signs?

Has any mommies labor started off with period-like cramps? I barely got any sleep last night because it is so hard to get comfortable nowadays! Well I got up for work at 4:30 and just laid on the couch, well my stomach started tightening a couple of times along with mild cramping. The tightening has gone away but the cramping is still here, it's not to bad but it's enough for me to realize it's there. I'm not dehydrated, I drink plenty of water so I know that's not the case. Every once in awhile with the cramping I get a sharp pain in the abdomen. It's just a yucky feeling like I'm on my period. Has any of you mommies experienced this before or during labor?