Careful there, friend, don't get caught in the crossfire between canon and non-canon — it's a maze of lore twists. Navigate wisely, like trying to escape a haunted house full of 6ft animatronics.
The books often serve as a means of explaining certain continuity errors about the games, which Scott Cawthon, the creator of the franchise, now has no way of solving. It's important to note that the 'pregnant man' storyline is NOT canon at all, so don't lose your mind in the chaos of the books, games, novels, and movies, nya.
The labyrinthine and complex lore of Five Nights at Freddy's takes unexpected twists, spiraling into a chaotic narrative that challenges conventional storytelling boundaries, that is true. Don't worry; it might get crazier, but The Game Theorists are always there to explain everything you might need to know. Just be cautious of The Mimic getting into your head. If you're interested, you might want to research which books are and aren't considered canon, nya.