Frustrated

Well I've been going to the gym for 3 weeks now and haven't lost a pound. I've been trying to eat more fruits and vegetables as well. I know that I have to be patient with it but I really wish that I'd see results now. I'm going to give it 6 weeks because they say it usually takes that long to see results with this kind of thing. I probably haven't lost weight because i'm building muscles up where my fat was and hopefully i'll soon reach the point where I'll start loosing weight. Nevertheless, I'm feeling frustrated.