The 57-year-old has been at Portman Road for almost four years and has enjoyed top-10 finishes in his three full seasons at the East Anglian outfit, including a sixth-placed play-off spot in 2014-15.
However, following an opening day 4-2 win against Barnsley, Town have scored only four goals in 11 matches since and have not found the net in this current five-game winless streak.
McCarthy accepts that question marks could be raised if he can't end the slump soon, but he is not worried about being axed.
"If people start wanting me out of the door there's nothing I can do about it except for work on the training ground and try to change that," said McCarthy.
"I prefer it when the fans are happy and want to come to the ground. The only way we'll do that is by scoring.
"I don't think I've suddenly become a bad manager," he added on BBC Radio Suffolk. "They might think it's not the bloke they want here any more, but not a thing I can do about that.
"Go back four years. If the club were in this position four years ago, who's phone did they ring? Apparently I've got lousy now, I'm not good and I can't do my job."