My son was 10 lbs 2 oz and I had one of those explosive looking bellies. You'd have sworn I was carrying twins.
Anywho, I wanted a boy and knew I was having one long before I was born. If I would've had a girl I would've been just as happy though. At the moment I am dying for a girl and hope to have a girl next time. If given the opportunity to choose genders I wouldn't though. It feels too unnatural.