Sleepy all the time!

Jacinta • Pregnant with my rainbow baby boy ☺️💙👶🏽🌈 due December 27th 2015!
I remember having no energy during my first trimester but I'm 35 weeks today and for the last week and a half I've been completely exhausted for no reason at all! Could this possibly be a sign labor is on the way? FTM and not really sure what to expect!