Considering his workload in the upcoming Test series against Australia next month, BCCI had wanted Shami to bowl not more than 15-17 overs.
"When you are playing a match for your state, the important thing is to fulfil your responsibility," Shami, who returned with 26-3-100-3, told reporters after the day two.
"I was also feeling well and had no discomfort. The wicket was also doing well so I continued as long as I could... I decided on my own," said Shami, who is India's highest wicket-taker in Tests this year.
Concerned with Shami's fitness issues of late, the BCCI had cleared the Bengal pacer to play ongoing Ranji Trophy match against Kerala on condition that he would bowl 15-17 overs per innings.
But as Bengal struggled to bundle out Kerala, Shami ended up bowling the maximum in the four-prong pace attack.
In comparison, Bengal's regular strike bowler Ashok Dinda bowled 19 overs, while youngster Ishan Porel and Mukesh Kumar bowled 18 and 14 overs respectively.
Shami said it was best to bowl in a match than in practice.
"It was better to bowl for your team and state rather than practising somewhere else... The more you bowl here the more it will help in Australia. It was good preparation. For me bowling in a match is the best preparation. I prefer that any day.
"I was feeling well to bowl at home after a long time. All my friends were here. It was after a long time I could play with my team," Shami added.
An integral part of the Indian fast bowling unit, Shami is the leading Indian wicket-taker in Tests this year with 33 wickets in nine Tests, including a five-for in the final innings of the Johannesburg Test that India won in January.
The four-match Border-Gavaskar Trophy will get underway in Adelaide from December 6.
"I've prepared well, had good training and match preparation. I have a practice match there. I will be ready for the Tests."
Bengal coach Sairaj Bahutule also echoed Shami's views on his extended spell.
"He was absolutely willing to bowl so he continued. Nobody put pressure on him," Bahutule said.
Bengal find themselves on the mat as they were 139 runs behind in the second innings with nine wickets in hand.
First Published: November 21, 2018, 9:59 PM IST