There are so many variables. First how close are you to your parents? Inlaws?
Can they be trusted to REALLY keep a secret if you ask?
As the mother, of course, I want to know as soon as possible, BUT, I understand the need of discretion, when my children are not ready to share the news.
Most wait until after the first tri-mester. Many wait longer for a various reasons. ie: a prior lost pregnancy, a yenta mentality on behalf of parents, you don’t show yet and you and your husband want to keep this wonderful secret to yourself.
I often know way before I am told, but I say nothing until they say something to me. I think this is a very very private issue and you and your husband need to what whatever makes you feel comfortable.