The defender was called up by Chris Coleman for Wales' final two World Cup qualifiers, but he did not make an appearance and was ruled out of Saturday's friendly against Finland due to a slight hamstring injury.
He remains eligible for England but is not thinking about such matters as he knows club form is the most important factor.
"I just need to concentrate on doing well for Newcastle. That is my main priority," Dummett, who could be fit for the Premier League clash with Norwich City, told the Evening Chronicle.
"I came back here in the pre-season and the manager rewarded me with my chance.
"It has been a dream come true - but I need to keep working."
While Dummett enjoyed training alongside Wales' top players earlier this year, he understands that he must keep showing the right attitude at Newcastle to ensure he gains further experience at international level.
He said: "It was a great experience to be training alongside Aaron Ramsey and Gareth Bale.
"The people at Wales told me to enjoy the experience and go away and keep working hard.
"For me it is all about what happens at Newcastle. We have had good results so we must keep that going."