Lilia Pregnant The World End is a Manga/Manhwa/Manhua in english language, SUGGESTIVE series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

After defeating the Demon King and saving the other world, the hero Takahiro returns to the real world. One day, Lilia, the daughter of the Demon King, suddenly arrives in Takahiro’s world, where he lives a peaceful life. Takahiro braces himself for her revenge, but her goal is to bear the strong Takahiro’s child…!