Prologue: I had an early m/c in late December. We had told my inlaws and my parents just before Christmas (the inlaws came for a visit before a month-long trip to Australia, and we had wanted to tell both families at the same time. Then again, I had already told my mom, but DH doesn't know that, and never will. She managed to keep it from my dad, though, which surprised me a bit). It would have been the 2nd GC for my folks and the first for the inlaws. We told our brothers (I have 2, DH has 1) the following day. Then, we had to tell the inlaws about the m/c when they called to tell us all about their trip. we had already told everyone else who knew a few weeks earlier, so it was hard talking about it again. Thankfully, my BIL had already hinted to them what had happened, so they were ready for the news.
This Time: I called my older brother the day after we found out. We are close, and he took the m/c very hard. He doesn't know it, but we're planning for him to be the godfather of the first child. I called my mom a week after we found out (about 5 weeks in) and asked her if she wanted to know if and when we got PG again. She said she didn't want to know until I was at least two weeks--no, a month--no, two months past--my AF. So I told her, "So I'll call you in a couple of weeks, then," and that was than. =) We told the in-laws about a week later during a weekly call with them. We never formally told my younger brother, but he figured it out after we went to watch a UFC fight with he & his wife at a local bar. We haven't told BIL yet, but he may be coming up for the weekend, so we'll probably tell him then.
The HR/Office Manager at my work knows, but she's keeping it mum. She's awesome for that. I probably won't tell my boss until a few months in. I work from home about 4.5 hours from my office, so it's not like we actually see each other. One of my employees knows--she recently had twins, and she knew about the m/c, but she doesn't have any contact with the home office, so it works out. Only thing is, I work in the wine industry, where it is considered an insult to refuse a wine tasting (especially since I'm dealing with the winery owners and winemakers most of the time). So, a few of the wineries know (which means, they probably all locally know at the rate word spreads in a small industry), since I just pat my belly and say "I would love to; maybe in about, say 7 months or so" when they offer.
My two closest girlfriends know (they pass the support test), and one other friend that is organizing a wine tasting tour for a whole group of friends in April (she was curious as to why I offered to be chauffer). And my cousin, who recently had a baby. I was freaking out one day and called her with questions.
We'll probably send a postcard announcement to the rest of the extended family once the doc has confirmed that everything is going well. Then at 12 weeks, we'll probably start telling more friends as we see them. (Funny story: we were actually with about 60 friends on an annual trip to Tahoe when the baby was conceived. We call it our little Snowball.)