When Lois first tells him that she's pregnant, he doesn't quite know what to think. At first he's delighted, as most people are when their wife is when she tells them they're pregnant. Then he's worried because he's not actually human and he doesn't know he's supposed to expect. But from what his father told him, they aren't that dissimilar, not that he won't do his best to make sure everything runs as smoothly as possible, even if he can't really take her to a doctor (because god knows what they'd find).
But despite all that he's happy.
How could he not be?