I announced my pregnancy ( been only pregnant once ) around 6 weeks. Although I had some people tell me "it's too early for you to announce it", I did it anyway. I was just so happy, I wanted to tell the whole world. My husband and I figured if everything will be good, it will be, and if it won't, it won't, no matter when we decided to announce the news. Luckily, everything went well. But, I understand how someone with prior miscarriage for example, would be reluctant to announce the news right away. But, no matter what, do it when you feel it's the right time. For some, it's as soon as they find out they are pregnant, while some people wait till they are in the second trimester or even later. Good luck to you!!!