When to spread the good news?!

How far along were you before you told your family that you are expecting? We just found out yesterday that I am pregnant through two positive pregnancy tests. My period is over a week late, so I believe I would be at about the 5 week mark. We want to tell our parents over Christmas, at the end of this week? Is it too soon to share the good news?? Should we wait a little longer before saying anything? This is my first pregnancy, so any tips help! Thanks!