What do I do 😳😩

So I'm period is late and I'm waiting till it's been about a week late to take a test. My problem is that my boyfriend is in the Air Force and left for ALS and won't be back in till December 15th. We've only ever had one other scare and I told him immediately. Do I tell him now or do I wait till I take the test? If it comes back positive how do I tell him? I feel like there's no good way to say any of this over the phone. What do you ladies think I should do?