We waited until the first big ultrasound. I believe it was at 18 weeks. However, we do have a special situation. DH's family is crazy when it comes to kids. Especially 2 of his sisters. You literally have to tell them to back off. They want to play mommies a little too much for my taste. So, we waited a long time to tell and when we did, it was accompanied with "Please do not call us every day to see how we are doing and please do not bother us with questions about the baby." It is that bad... After DD was born, one of his sisters decided it was her place to take care of MY baby... That flew with me like a ton of bricks. She even got offended when we did not let her bathe DD. She has had her 3 kids. This is MY experience!!! I am not letting anyone bathe my baby, especially the first time!!!
Plus once everybody knows, you start getting a lot of advice. While some of it is great, most of it will make you want to puke even more

Beware!