How Did Bellatrix Get Pregnant?

Yep, that happened: Bellatrix and Voldemort had sex sometime around Order of the Phoenix or Half-Blood Prince, and their wild night in bed led to a child named Delphi Diggory/Riddle/Lestrange. According to Delphi herself, she was born sometime before the Battle of Hogwarts.

Was Bellatrix pregnant in the Half-Blood Prince?

Helena Bonham Carter, who portrays Bellatrix in the films, was pregnant during the filming of the film adaptation of Harry Potter and the Half-Blood Prince. Her pregnancy seems noticeable (but not too far along) during the scene at Spinner's End.

Was Bellatrix pregnant in Deathly Hallows?

When was Bellatrix Lestrange pregnant with Voldemort's child? So we all know by now that Delphi Diggory ain't Delphi Diggory. Nope, she's the child of Voldemort and Bellatrix Lestrange, who was born at Malfoy Manor just before the Battle of Hogwarts.