Gender reveal party

Michelle
My husband and I are throwing a gender reveal party the weekend after we find out the sex. Me and my husband want to know at the ultrasound and I think it'll be fun to know and watch everyone at the party guessing or trying to make us tell. 
Some of my coworkers think that I should find out right along with everyone else but I don't want to lol  
Anyone else do their party this way?!! How did you reveal to your family? Cake? Onesies?