I honestly spent way too long going back and forth about if Giles was a jackass for asking about having kids like that or Buffy was for announcing an unplanned pregnancy like that. But then I decided that, as newlyweds, they had probably agreed to a "whatever happens, happens" approach with plans to revisit the conversation at some point in the future. So Giles was just asking if Buffy was ready to discuss things again, except "whatever" happened already. ;-)