I swear, throughout the day, I will just get smacked over the head with exhaustion. There's no set time or triggering action, I just get suddenly tired. And not cute sleepy tired, bone tired to where all I want to do is lie down and not think or move. Ah, well. Halfway through, and my baby boy (I'm still reeling over the fact that I now know I'm having a son!!) is growing all nice and normal. It'll all be worth it in the end, right?