Congrats Ren!
Seeing and hearing the heartbeat is the most amazing thing. I got a dvd recording of a scan I had at 32 weeks and it has the heartbeat so I can listen whenever I want.

I wouldn't worry about the dates. When I had my scan at 5 weeks and again at 7 weeks, the sonographer asked me when I thought I was due based on LMP and he said that it will probably be wrong and when he did the measurements, his dates matched my dates! So I kept the same date all the way through based on my LMP but they say plus or minus 3 days. In the end it doesn't really matter because bubs will come when he/she is ready - like my little munchkin came 3 weeks 1 day early!

Woohoo again now the wait for the 12 week scan!