Do fathers ever really "come around"?

If your boyfriend was showing no interest in your pregnancy (not talking about doctors appointments, the baby, your future together, no excitement whatsoever, etc.) would you leave him? This baby was a surprise for both of us but I have obviously chosen to keep it against his wishes. We live together but whenever I bring up the baby he acts like he doesn't hear me/doesn't respond and it's starting to get frustrating and hurtful. People keep telling me "he'll come around". It took two days for me to come around so to speak but it's already been almost 3 weeks and nothing with him. Anyone else been in this situation? I want us to be a family but I'm not waiting for him to grow up.