When to announce

My husband is deploying soon & the announcement options we've come up with are

6 weeks: right before he leaves & after I've had my intake appointment where they'll draw blood and make sure my hormone levels look good, but no ultrasound to see a heartbeat

12 weeks: out of the first trimester into the "safe zone" as far as miscarriage risk, BUT he'll be gone

~16-20 weeks: he'll be back & we could do a combo pregnancy/gender announcement at the same time, but that's basically halfway through and a LONG time to keep the secret

....So, which would you choose & why?

My concern with 6 weeks is that I've had 1 miscarriage and without at least seeing a heartbeat, I'm nervous to announce(I also have 1 healthy son though, who we announced at 4 weeks). With 12 weeks is that I feel like he should be here for the announcement but he's said he's ok missing it. With 16 weeks is that it's just such a long time to have to keep the secret.

We live so far away from family there is no chance they'll find out before we tell.