How long will you wait to tell friends and family?

Melissa • I`ve had 3 preg I lost the first then had my rainbow baby then I lost my son this year trying for baby 4(1 living child)
I don't know when to share the news... I almost don't want to say absyrhingbabd just show up with a baby but that's unrealistic lol I was thinking about waiting until I was 20weeks sonics I lost my son at 17weeks. Any thoughts?