Yep. That means twins.

"Okay, I see two heartbeats and two amniotic sacs." (pause) "You did know that, right?"

Long story short, my first ultrasound was not done by my normal doc, so he assumed that I knew about the TWO BABIES. WHICH I DIDN'T. And I don't really remember a darn thing about the rest of that visit. Except that my heart was racing. Yes, I can say that it was quite a shock when we found this out!
I'm 12 weeks along now, and we've known since about week 6, so I'm past the shock to a pretty constant excitement. I love that our kids will be so close in age, and so, hopefully, in relationship with one another. I can't say that I would have chosen things to be this way (and I'm sure I'll really feel that way when I'm caring for two newborns and a two year old!), but I feel oh so grateful that God has chosen this for us. No matter how or when they arrive, children are a treasure, and we are so happy anticipating such wealth times three!
If you think of it, pray for us. While there are no indications now that there will be any problems or complications with this pregnancy, twin pregnancies do have a very high rate of miscarriage, premature birth, birth defect and even SIDS deaths. I must admit that I've had some pretty disturbing dreams to that effect. Time to stop browsing the internet for twin info, I think.
For those who are curious about the fact that Ben is a twin, that is not likely a factor in our having twins. You see, Ben is an identical twin. It's not known exactly what makes the egg split to create identical twins, but that phenomenon is not considered to be hereditary. And indications are that ours are likely fraternal (though not certain without a DNA test).
We'll keep y'all up to date as the pregnancy progresses. The top pic here is from about a month ago and shows both babies. The lower shows just one of them. Lovin' them already and counting down to the due date, November 9!