If I go again, I'm never telling anyone outside of very close people! I told someone from a homebirth support group I was a part of and she assumed that another mutual friend knew and talked about it, only to realise this friend didn't know. Now, to be fair, she knew that the mutual friend is a particularly good friend of mine, but she wasn't to know that this friend couldn't be trusted with news because she'd tell her husband (and only her DH), and HE is the one with the big mouth. Guess what? Friend told her DH and he went round telling people, even prefacing it as a rumour...without checking with me or DP first! We were supposed to be all good friends till that point! Coincidentally (or maybe not, there may have been some unconscious anger there) the two fellas had a falling out over something unrelated and haven't really recovered from that.
Moral of the story: Keep the news VERY close, and if leaving out some close people, don't tell further related people!
Stick to your announcement plan and let the rumour mill go.
In my story, I didn't show till I was about 21 weeks pg, so a lot of people thought this guy had made it up for a good two months