The defending Premier League champions are 15th in the table and have won three league games this season.
“I am not worried about my job. I am not worried about my future,” Mourinho said ahead of Saturday’s visit of Liverpool.
“I don’t spend one second of my day thinking about it.”
He added in his pre-match media conference: “It looks like you want to put a lot of pressure on me in relation to that, where you can’t do it. You can’t do it.”
Reports have suggested the 52-year-old could lose his job if the Blues are beaten by Liverpool on Saturday.
But Mourinho refused to comment on whether he has received reassurances from Chelsea’s board and owner Roman Abramovich about his future.
Asked if he had been given a guarantee, Mourinho replied: “I don’t have to tell you.”
In August, Mourinho signed a four-year contract extension until June 2019, but Chelsea have suffered the worst title defence since the Premier League began and have lost half of their 10 league games this season.
Abramovich has previously dismissed managers when Chelsea’s place in the Premier League’s top four and qualification for the Champions League the following season had been in doubt.bbc.