Labor questions

Ok moms that have recently delivered or any moms that remember their labor experiences. I'm a FTM expecting today September 3rd. I haven't really had any indication of labor at all and in fact as of my last check on 8/31 I wasn't even dilated at all just 75% effaced (which I have been for 3 weeks). My question is today on my due date I suddenly feel exhausted. Like I've already taken 2 naps today and my entire body aches all over like I did a serious workout or something. Do you think I'm getting sick or do you think perhaps labor is near? Anyone remember how they felt right before labor?