Well, I told DH, of course, though actually, I told my yoga teacher first.

See, DH got home JUST in time for me to leave for my yoga class, so I didn't have time to tell him before going, but I wanted my instructor to know in case there was anything she'd want me to modify. But then I told him as soon as I got home.
I've told a close group of on-line friends. I'll tell my acupuncturist, who is also a friend, on Friday. My MIL is visiting this weekend so we'll tell her then. My parents/family I'll probably wait until I see them in person the first weekend in August, though my bro prolly won't be around, so we'll see. I'm DYING to tell my IRL friends, but DH wants me to wait until we've told the families.
We haven't told DS [4] yet, just in case, and also because I want to move him out of the nursery into his "big boy" room before telling him, so that he won't feel evicted.