A Chris Wood goal in the first half was enough to seal the points as Wednesday missed a second half penalty.
But Carvalhal saw enough of a fiercely contested derby display to indicate positive signs for the remainder of the season.
He said: “I thought the first half was very even apart from one second of concentration and Leeds score the goal.
“Then in the second half we have the chance to score with the penalty and the goalkeeper makes the save.
“But this is football and these things happen in football. It is now about being strong and coming pack positively in the next game.”
“But the signals are positive because we came to Elland Road in a big atmosphere and were the better side in my opinion.
“We deserved at least a point but we did not get it so we move on.
“Three of our next four games are at Hillsborough so we need everyone who loves this club to help make an impact because we are at the most important part of the season.”