A 25-year-old man accused of the murder of a 30-year-old nanny in Portlaoise two years ago has told the Central Criminal Court he never set out to kill her.
Robert Corbet, of Sheffield Cross in Co Laois, said he was sorry Aoife Phelan's death had happened.
He claimed he saw red and lost self control after she threatened to ruin his life.
Mr Corbet admits killing Ms Phelan in October 2012, but he denies murdering her.
The trial is now reaching its closing stages.
Mr Corbet ran his own haulage business after the death of his father in 2010.
He said he first met Ms Phelan in a night club at the end of June 2012.
He said they had physical contact just twice after that but that there was frequent communication between them via text and the WhatsApp mobile phone application.
In one of the texts, she told him her period was late.
He said they discussed how they would deal with a possible pregnancy.
Mr Corbet told the court today he was frightened and offered to help her pay for a termination.
However, he said they also discussed baby names at a later date and he was starting to get excited about the pregnancy.
He said he believed her when she said that she was pregnant and that he was the father.
He said he had just come out of a long-term relationship and did not really want another one but you would not know what would happen down the road.
He said that when he first met Ms Phelan they used to have good fun and banter but messages between them then became all baby related and he told the court "it just done my head in".
Mr Corbet said he arranged to meet Ms Phelan on 25 October 2012, as he wanted clarification about the pregnancy and he also intended to tell her he was going to New York the next day to visit his ex-girlfriend.
The court heard there were frequent messages between them on WhatsApp with highly-sexualised content.
He said she became angry after he asked her what was going on with her pregnancy.
He claimed she got very angry and made threats that she would ruin his life and his business.
Under cross-examination he said he did not know how she would ruin his business.
He said the protective instinct went off in him as he saw someone threatening everything he had worked for and he just snapped.
He said he caught Ms Phelan around the neck with his right arm.
He said they fell to the ground and he kept his grip. He said it was very surreal and felt like an out-of-body experience.
He said it was a loss of self control and he just could not stop.
Mr Corbet then said he put a black bag around Ms Phelan’s head and put cable ties around her neck before dropping her body in a barrel.
He later put the barrel into a pit he had dug a few weeks earlier on his land and arranged for the pit to be filled in the next day.
He told the court he had panicked.
He said he told lies to gardaí because he was afraid.
He said he never set out for any of this to happen and that he was sorry for what he had done.
Mr Corbet said if he had not been arrested he would have handed himself in.
Prosecuting counsel Isobel Kennedy put it to Mr Corbet that he had told complex convoluted lies to gardaí.
She said his actions were deliberate, organised and calculated, and very far from the actions of a man who was panicking.
She said he had managed to eliminate Ms Phelan from his life.
He said he had never set out for that to happen.
Mr Corbet said he said certain things to gardaí in interviews just so he could get back to his cell and take his own life.
Ms Kennedy said gardaí checked him in his cell every ten minutes and on most occasions he was snoring.
Ms Kennedy put it to him that he was not acting under provocation.
He said the threats caused him to snap. She asked him how Ms Phelan was going to ruin his life with a pregnancy in 2012.
He said he did not know. She said he was a careful person acting in a calculated way. He said there had been a loss of self control.
He told his own defence counsel, Conor Devalley, that nothing he could say or do would replace the loss the Phelan family had had.