When to tell family

Theresa • Met my husband through World of Warcraft. Now 6 years later we are married (10/17/14).
So hubby and I just found out we are pregnant.  I am 36 so really nervous about this even though many people tell me it will be fine, and members of my own family have had kids after 35.  How long before you feel it is safe to tell family and friends?  My best friend (my age) is pregnant with her second (a week ahead of me even!!) and said they wait until they hear the heart beat the first time.  I know the moment we tell my mother she will begin plans to invade us (she is retired, dang it!)  just unsure when to say anything.