38 weeks pregnant tomorrow and today...

I've been having mild back aches and pains today. Some contractions here and there that have actually been painful (I have only been experiencing Braxton hicks so I know the difference now)... on top of it I have been really gassy ALL night and just now spent an hour on the toilet with diarrhea... I haven't gone in a while so I don't know if this has anything to do with this. I know TMI... but seriously, ladies is this normal?? I hear "going" a lot and being gassy is a sign of your body clearing itself for labor. Is that true???? Anyone else experience this ever???