The same thing happened to me Tuesday, the doctor couldn't find the heartbeat, but I was psyched because I knew she would send me downstairs for an ultrasound! The good thing about feeling awful is I know the baby is ok!
I told my supervisor today. He is a good friend, so he went through the full range of emotions from "Oh my gosh, you're starting all over??" to the horror of having to pump in our all-male office... very funny. We decided to keep it quiet and see how long it takes anyone to notice.