Until proven otherwise, I am convinced that there is no baby, that Lex faked the pregnancy to force Lana's hand in marriage. I could be mistaken, but at any rate I don't think he is going to be a father; if she's got something growing in her, it's not his seed. Or else it's not going to come to term. Mainly because I think if Lex did have a child now it would knock him off this dark path, because he would have someone to love. I don't think Lex, with all his need for love, could help loving his own child (even comic book Lex Luthor is weak to his own offspring, from what I've heard, though his love might take some twisty angles...)