My teenage daughter told me she was pregnant, what should I do/say?

I had an unplanned pregnancy and had twin girls when I was 14, it was a lot of work and sacrifice and I hated the pregnancy at first and wanted to get rid of them, but I came to love them more than anything, they are beautiful, smart, and we are very close. But one of my twins today told me she was pregnant, which I never thought would happen because she had been so much more responsible than me for the most part and she told me her and her boyfriend used protection. I knew something was going on for awhile and she was uneasy, when she told me hugged me and started to cry. She fell asleep next to me in bed and I haven't said anything more about it yet because she's still asleep. I love her and her twin more than anything, but I don't know what to say. What would you do if she was your daughter?