Thanks ladies! Good to know there's no absolute rule when it comes to telling the people close to you. I talked to DH about it last night. We agreed I would tell my parents on Mother's day. We will tell the MIL in the second trimester (she's not the best at keeping secrets).
As for my friends, I'm still undecided. This weekend is my birthday, so I was thinking about inviting them out for brunch and telling them. i just can't keep it to myself!!! Also, one of my besties is pregnant with her first as well, and I want to talk pregnancy things with her. Plus, if the worst DID happen, I'm pretty sure I would need their support anyway, so I might as well tell them now.