Newcastle sit bottom of the table without a win following Saturday's 1-0 reverse at home to Brighton.
"We dominated from start to finish, and they had one opportunity on goal and they scored from a set-piece that was never a corner to them," Dummett said to 'NUFCTV'.
"But we have got to be more clinical in front of goal when we get the chances because we had plenty of possession, plenty of chances and we didn't finish them off and in the Premier League, you get punished when you don't take chances.
"We can't feel sorry for ourselves, we have got to carry on going because it's a long old season and we're still just at the start of the season now and a few wins can take you back up closer to the teams around us."