Miscarriages

Tara • 02.22.16 ZJLA Baby #2 is on his way!!!!
I don't want to tell my immediate family too soon. But I also want to tell someone! I am 4weeks today. I found this chart online, so I was thinking about saying something at 5 weeks since I'll officially have a missed period and only a 17% chance. I read on another website that weeks 3-4 have a 75% chance! I about died. 
When does everyone else plan on telling their parents/siblings