Let me just offer a word of caution - if you decide to tell a few people early, that's great. Honestly, it made me feel better to tell someone instead of bottling it up for 12 weeks.
But be prepared that word *could* get out if any of those people are bad about keeping secrets. My mom told her mom, who then told my aunts about it. I wasn't ready for them to know quite yet, so it was irritating.
Just make sure you can trust the people you tell. :)