Father's day woes-what should I do?

At first, he was saying things like " I don't want you to keep it but I'll stand by whatever decision you make." and a few common other statements you would typically expect from a teen, not a man in his 30's. Recently, we have discovered that we just don't mesh in a relationship...at all! Friends, we're cool, other than that, NO. I decided I wanted to keep the baby, I love kids. But now it's father's day, and I called him, he told me he didn't know how to respond with the token "happy father's day" phrase. This is kinda the final straw for me. He's been saying things like: it's not his, he's sterile, 'are you sure?'. To me, it's like slapping me in the face and saying he doesn't want anything to do with me or the pregnancy. He's acting like a jerk! I'm in my late 20's, have a great career and can take care of this child on my own. I've called him, txted him ultrasound pics, everything to get him more excited/involved. Nothing. No happiness. Should I walk?