The Magpies boss said: "Of course promotion is our priority, but the cup is a big competition.
"We are still in the hat, which is what counts, and will be in the fourth-round draw, which is important because it's a competition that we want to do well in.
"I felt we were a little bit unlucky and I felt that if there was one side that was going to win the tie it was going to be us.
"There were long periods in the game where we dominated and perhaps just lacked a little bit of guile or fortune in the final third that would have seen us score a goal on a very difficult pitch and overall I thought we were the better side."