Hey T.!
Congratulations on your new baby! That's so exciting!
When we finally get pregnant with our second, I want to put our little girl, Emma, in a shirt that says "Big Sister" and have her casually wear it around family, friends, whoever I'm telling, and see how long it takes them to figure it out! :-)
Another fun idea is, if your family lives out of town, send something like a cookie bouquet (or flowers or something) decorated to tell them the news.
Or, I used to work in a stationary & invitations boutique in Plano, and we did TONS of Christmas Cards... in one of my favorites, the couple already had 3 kids and was having another. So their Christmas Card picture was of their 3 kids each holding a sign (one said "It's" one said "A" and one said "Girl!"), which together, spelled out "It's A Girl!" I thought that was so fun. Obviously you don't want to wait until Christmas, but you could do something like that, sent in a frame to your family or sitting out for your husband.
Have fun and blessings in your pregnancy!
S.