I only have a minute, but...
I was in "labor" for three days, but the contractions had been happening off and on for a couple weeks before that. There was definitely a difference when they kicked into gear; a sharpness to them that wasn't there before. But they'd kept me awake and interfered with my life for weeks. I was due August 15th, started prodromal labor August 11th, and didn't have the labor really start until August 26th (finally had the baby August 29th).
I know they say that all that prodromal labor gets the cervix ready--but it didn't. I'm sure it was doing *something*, but it wasn't doing anything that we could check for. So don't feel discouraged when your cervix feels the same day after day.
So yeah, labor can seem to drag on forever. I'd been avoiding doing anything by myself, staying well rested, expecting "real" labor at any moment, etc... finally, I stayed up late one night watching a movie with DH, and the next morning had gobs of bloody show and the contractions were much more intense.
So... you're doing it!