The Stranger Within (1974)
Although her sweet, caring schoolteacher husband David (the fine George Grizzard) had a vasectomy three years ago, successful painter Ann Collins (marvelously played with meticulous focus by the lovely Barbara Eden of "I Dream of Jeannie" fame) has somehow managed to become pregnant. Even weirder than Ann miraculously having a bun in the oven is the radical shift in her once normal, now increasingly flipped-out behavior: Ann starts putting way too much salt on her food, gulps down steaming hot black coffee by the gallon, develops a peculiar predilection for freezing cold temperatures, reads sociology books by the dozens, starts talking in an odd unidentifiable foreign tongue, and becomes cranky to the point of being downright hostile. Is Ann going crazy? Or, more disturbing, is the rapidly developing fetus she's carrying some kind of alien creature with potentially malevolent intentions?
This frightfully effective and absorbing made-for-TV domestic sci-fi/horror hybrid mixes elements of "Rosemary's Baby," "The Exorcist" and "The Stepford Wives" into a highly creepy and compelling synthesis... (IMDB Woodyanders)