When to tell the boss?

I work from home and don’t see my bosses regularly. The office is 4-5 hours or a flight from my home. I’m a regional director. Tomorrow I’m 6 weeks pregnant. I’m going to the office this week for meetings. Last time I’ll see either of my bosses until I’m 16 weeks pregnant at our next meeting. Should I tell them now in person and create a plan for leave or wait until I’m further along and call them to tell them? My big boss isn’t really personable. My direct boss is like a big brother and knew we have been trying for two years. There is a big project due before the end of the year and our company is going through a bunch of changes. This makes me nervous to tell right now. But I don’t want to wait and they see on Facebook or something like that.

Need advice- when would you tell your bosses if you were in my position??

A. Tell now at 6 weeks

B. Call on phone at 12 weeks

C. Tell in person at 16 weeks