how did you tell your work?

I'm 9 weeks and will wait until 13 weeks but starting to prep in my mind how I'm going to tell my boss. I work in a male dominated industry and my boss is rather *very* chauvinistic. Sad that in 2016 I have to prep my work announcement. I think I'm just going to go in strong and proud and tell my boss point blank - show him his opinions mean nothing to me and my joy. Any similar issues with you ladies at work?  How did you make the announcement?