After reading the books, we were surprised about the ultrasound too. I think the doctor thought that it was further along than it turned out to be, and I think she's also cautious. She wanted to do blood tests after that to make sure everything was ok, but I talked her out of it until the next time I went in (the nurse had already promised me there would be no blood tests that time). Honestly, even though the test hurt (for very little), I really can deal with any kind of pain that's not a blood test. I don't know. So I'm not worried about the other things I've read. Well... unless we have to do that amnio thing for any reason. They're going to have to sedate me if they think that's happening.
And that's awesome that you got to hear the heartbeat (and that it's only one). I look forward to that. Any tips or things to expect you have to tell me about, I'd appreciate.