Sometimes it feels more like the LDB used to be an actual dragon.
But for some reason the divines put him in the body of a human,
maybe as punishment or lesson,
or maybe the only way for a dragon to be born at all is in the body of a human.
seeing as no new dragon can be created or born.
Neither.
Dragons don't reproduce nor have they ever. They don't have biological gender. They're Aedric spirits given flesh. They have always existed, and simply are.
They're like fragments of the Time Soul, and when they die in presence of another fragment, they merge. dovahkiin are mortals with a fragment of the Oversoul in them.