We told family as soon as we found out at 6 weeks but I didn't make my a announcement on Facebook to friends until 12 weeks :) I had to tell management at work earlier because my morning sickness was horrible.
I waited until first ultrasound at 8 weeks to tell (except my older sister who bought me the home tests). Then I only told close friends and family until 13 weeks. Hard to keep that secret!
I was excited but I waited. 10 weeks for baby 1 and 12 weeks for baby 2 (had my son in a big brother t shirt for the reveal). before that only people who knew was my husband and my sister