I am currently in a master's program, but am waiting to hear if I got into a PhD program. When I first applied to graduate school I was a nervous wreck. Until I heard from my first school I couldn't sleep, and when I did I had nightmares about my applications. I am much better this time around (though I have had my share of nightmares). I think the best thing to do is to send your applications in and then do whatever it takes to keep your mind off of the process. The letters will come when they come and worrying won't hurry up the process.