25-year-old Robert Corbet of Sheffield Cross claims that he "lost self control" after Aoife Phelan provoked him.
On Oct 25th 2012, he strangled her to death in his garage after she allegedly threatened to ruin his life over the pregnancy.
A post-mortem revealed she wasn't pregnant at the time.
Robert Corbet pleaded guilty to her manslaughter from the outset of the trial but denied murder, He claimed he was provoked and didn't intend to kill her.
In a statement read out in court, Aoife's mother described her as "beautiful, bubbly and happy" while her father spoke of his heartache in never being able to walk her down the aisle on her wedding day.
Robert Corbet looked distressed before and after the verdict was delivered and he has now been taken away to begin a life sentence behind bars.
98fm's Frank Greaney reports:
