Transitioning from working woman to working mom

Kris • Expecting baby #1 in June 2015 :)
As I get further along in my pregnancy I find it so hard to focus on work. Overall, it is just getting harder to be in work mode and focus on huge projects when I feel like I'm already working on the biggest project of my life - becoming a mom. How are you all balancing work with becoming a first time mom and everything that comes along with that? It was easy in the beginning but now that I'm in my third trimester, not so much.