Rent Devil's Due (2014)

A young couple's blessed event turns into their worst nightmare in one of the most terrifying horror films ever conceived! After a mysterious night on their honeymoon, Zach (Zach Gilford) and Samantha McCall (Allison Miller) find themselves dealing with an earlier-than-planned pregnancy. While recording everything on video for posterity, Zach notices odd behaviour in his wife, which they initially attribute to nerves, although it soon becomes evident that the disturbing changes to Samantha's body and mind have a much more sinister origin.