Spoilers for Game of Thrones season 6 and 7 ahead.
Just before Ramsay dies at the teeth of his own rabid dogs, he makes a prediction in the face of Sansa Stark: "You can't kill me. I'm part of you now."
The first part of Ramsay's theory is destroyed immediately, because Sansa Stark quickly ends his life via the aforementioned hounds.
The second part of Ramsay's theory, that he's "part of [her] now," is currently being put to rest by none other than the Onion Knight himself, Ser Davos Seaworth, also known as actor Liam Cunningham.
Many fans interpreted Ramsay's warning as evidence that Sansa was pregnant with his child. But Cunningham refuted that notion as ridiculous in an interview the Huffington Post:
Unless he’s got one of those ‘Game of Thrones’ pregnancy sticks, he’s not gonna know [that she's pregnant]. I think, I would imagine, it’s open to whatever you want it to be, but I think he’s saying he’s put himself into her head. That’s what I took from it. She’s never gonna get rid of him because of what he’s done to her. He knows what he’s done to her. It was off camera, what he was doing to her, but we all know what it was. But I think he’s placed himself in her soul for all the wrong reasons.
Cunningham's denial comes despite what some fans pointed to as further proof of Sansa's pregnancy, a line in "The Door" when she tells Littlefinger: "I can still feel what he did, in my body, standing here, right now."
Cunningham insists those line are all metaphorical. So has Sophie Turner.
However, if you don't believe Cunningham or Turner regarding Sansa's pregnancy with a Bolton-demon (which is reasonable, considering Jon Snow straight up lied to us about his death over and over again), take it from premier GoT fan site Watchers on the Wall.
They're constantly breaking spoilers with insider sources, and now they're confidently asserting that "Sansa will NOT be (or get) pregnant in season seven."