The Last Trimester (2007)

Eric Smythe marries Tracy, whose father gives them a house to raise a baby, but due to her fertility problem they opt for an adoption, which falls trough. Then Eric gets pregnant acquaintance Gabby to agree to let them adopt her baby, in exchange for financial support. She wriggles herself into their lives and home, extorts ever more money and stalks Eric, only to expose his secret when turned down. Gabby disappears, police detective Nick Hanford investigates and quickly makes Tracy doubt Eric.