I'd go ahead and tell you're family and close friends, like the previous posters said the risk gets smaller as time goes on... You've also got to ask your self that IF you did miscarry in a couple off weeks would you rather have to deal with it alone, or with the support of friends and family... it's your choice to make at the end of the day Xx :-)
Congratulations!! The safe zone is indeed 12 weeks as at that point you can see from that scan the baby is growing well and the heartbeat in ok. Its personal opinion of what u class as the safe zone. For example i have recently mc so this pregnancy i wont tell anyone till 12 weeks. Good luck :-)
If youre 8 weeks and everything is looking good go ahead and tell when youre ready! I believe the 'safe zone' is 12 weeks. But the chances if losing a baby get smaller and smaller as the weeks pass. Id say youre probably safe! So you make the decision! congrats!<3