Why are you suprised that he wants nothing to do with you or the baby? Did he talk you out of a termination and then leave you stranded? You'd only been together for three months - it's not like you were committed or anything.
And why is it that a woman has choices about motherhood but a man has no choice about fatherhood? If a woman doesn't want to be a mother, most women will support her choice to either abort or adopt. But if a guy doesn't want fatherhood, he's called every name under the sun as shown in the responses you've received so far. Such a double standard.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.