Telling family and friends

I'm 6 weeks and 2 days I don't go in for my ultrasound until the 28th however I have my college graduation this weekend and my husband thought it would be a good time to tell everyone. We have told our parents and siblings already but is it to early to tell the rest of the family? We are having a party so it will be hard to hide  when people realize I'm not drinking. Suggestions?