It took me till the end of the movie to get it. I looked at my kid and said, “prequel to Alien.” My kid then asks how could the good Dr. Shaw give herself a cesarean and 500 years later, Ripley is telling the doctors to get this thing out of her.
That was the first face-hugger in her womb, not an alien implanted in her chest by a face-hugger.
There’s a difference there!