Do we find out gender?

My bf and I originally wanted to find out what we are having. I'm type A personality and a huge planner, as is he! But now that we've told family and some close friends, they're telling us we should let it be a surprise. So now we can't decide! We have 4 weeks until our next appointment. What do you all think or what did you do? Do we find out or keep it a surprise?