Beyond the Door (1974 film)

Beyond the Door (Italian title: Chi sei?) is a 1974 Italian-American horror film directed by Ovidio G. Assonitis (credited as Oliver Hellman). The film stars Juliet Mills and Richard Johnson, and was released in the UK in a re-edited format as Devil Within Her.
Plot
Jessica Barrett is a young mother in San Francisco. Her family and friends begin to notice odd behavior around the time she falls pregnant with her third child. As the strangeness intensifies, Jessica begins to display signs of demonic possession including spinning her head all the way around and projectile vomiting.
Dimitri, a lover from her past, shows up claiming to be able to help her, but it turns out he is in league with the entity possessing her, and is aiding the birth of her child, assumed to be the Antichrist, in exchange for the thing saving his life years before. The film ends with the entity turning on Dimitri, and suggesting all events were...