Can a doctor know at 10 weeks the sex of baby?

Yes you can have a sono at 10 weeks.........we had a vag. sono at 8 weeks and we were able to see the baby and hear and see the heart beat!!! It was amazing i am going on 10 weeks tomorrow 12/27/2007 and am feeling great. Just remember to surround yourself with amazing people and relax this is the best experience even if it does not feel like it right now!