I think my 17 year old brother is going to be A DAD?!?!!?

Ask your brother to hang out with you for an afternoon (go get a bite to eat, walk etc) and ure him that you are there for him if he ever needed anyone to talk too. Just make small chit chat.Try to find out about his social life and if he brings it up, then you can discuss it. If not, leave it alone. It may not be as bad as it sounds, it could be a friend he knows that is pregnant or maybe he is dating someone pregnant. Well good luck!