I am so tired- help!

I just found out that I am pregnant for sure (yippee!!!) and I am 4 weeks and 4 days. I am delighted, excited, ecstatic and joyous- but man am I tired. 
I work full time and don't plan to tell anyone around me til 3 months- how are you ladies dealing with the exhaustion?
Power foods? Power naps?
Thank you in advance!
-Excited mommy to be!