Wow, what a story! Glad it's turning out to be happy news all around :)
I had an u/s at 6w3d and 6w4d with my two, for a heartbeat check (due to previous early m/cs) and dating. It's very accurate that early, so I definitely think you should make the call sooner rather than later. If it's too early to see anything, they'll be able to tell that too.