We and my girlfriend would be very upset, depressing and even talk on a bad way to each other on the following days after knowing. However, we're both lucky we're very supporting to each other, so, I would support her, and I know she would support me on such a big loss for our relationship. Since we've already talked about lots of things, like marrying, living together, babies, their names, how to educate them. It would be such a great loss, we are both waiting for the right time (I'm 16 atm, so... >_> it's still some years from now) for it, since we're both desiring to have such "fruits" of our love, and only those who really know what Love means would know its meaning and what this theme means and how important it is.
Basicly, me and her would be very depressed and would rely 24:7 on each other's support and wouldn't care about anything else until the fact "settles", then, I'm not sure if she would accept adopting a kid.