we weren't going to with DS... but then we did. and we weren't going to with this one... but at the u/s where they found my fibroid, they asked if i wanted to know, and i couldn't help myself!! i'm terrible with surprises. i ALWAYS want to know. we're trying to keep it a secret from everyone else, but i'm bad at that, too.
so we already know (although 12 weeks is pretty early to be 100% sure about it), but we're not telling.
(by the way, it was good that i found out with DS because both DH and i were convinced he was a girl, and it took me until he was born - and even a little longer! - to get used to the idea that he was not a she!)