"No Period" is a short story by Harry Turtledove, published at Tor.com on November 30, 2020. Its genre is ambiguous.
The piece is not structured as a conventional story. It begins mid-sentence as the unnamed narrator, a Jewish man living in the United States, begins to contemplate his failed first marriage, and then wonders what changes he might have made in his life to save it. Then he begins to think less about his personal circumstances and more about the broader course of history, briefly contemplating and discarding alternate timelines in which he and his first wife might have made it work, going back to World War II, the age of Napoleon, the expansion of the Mongol Empire, the Maccabean revolt against the Seleucids, Homo sapiens and the Neanderthal, and even a world in which the dinosaurs did not go extinct. As he contemplates each scenario, he sees circumstances that would ultimately end in the failure of their (or their close analogs') marriage. He soon realizes that there is no period he can alter to save his marriage. At the end, the narrator concludes his life is pretty good. The last words of the story circle back to the first line of the story. The story doesn't use the period as part of its punctuation; it is one long run-on sentence reflecting the frantic stream-of-consciousness of the narrator, which then loops back to the beginning.