Girlfriend is pregnant and unhappy, what to do?

My girlfriend and I have been dating for 3 months, prior to being together we were both in serious relationships. Mine was 5 years, hers was 8 years. Commitment is not an issue and we both intend on being with each other for the remainder of our lives. With that being said, she's always said that she's wanted kids, but not right now. Yesterday we found out she's pregnant and she broke down in tears, we took 3 different home pregnancy tests and all of which confirmed the pregnancy. For the past 2 days she's been very closed off and not talking to me. The only time she does talk to me is when she's complaining about how much her life sucks and how this kid is going to ruin her life. She keeps telling me that she doesn't want a kid and she's not going to be able to do anything that she's wanted to do. She's 27 years old, drinks (but says shes not going to now), Smokes (Says shes going to keep smoking). I know I'm just rambling now, but I need someone to make me and her feel better about our situation. I'm happy, and because she's so unhappy, it makes me feel bad to know that I'm this happy about it and she's miserable. Do you guys think she will eventually get happy when she hears the heartbeat or even holds the child in her arms? She says she's not going to feel any differently. Make us feel better guys.