The Red Devils threw away a two-goal lead twice to the Premier League newcomers at the King Power Stadium on Sunday afternoon.
However, Van Gaal has said that he is not panicking after his side's slow start to the season.
"I cannot say that I am happy, but in the world of football, these matches happen," the Dutchman told BT Sport.
"In my first year as trainer-coach of Barcelona we were 3-0 ahead (against Valencia) with a quarter of the match to play and we lost 3-4. It can happen.
"We had the game in our pocket, but we gave it away. That I don't like, but I am convinced we shall improve."
United are 12th in the table following the defeat.