The 19-year-old scored PSG's third goal to put them back in front after a dramatic fightback brought Nimes level from being 2-0 down, but he was dismissed in the dying seconds for his reaction to a rash challenge by Savanier, who was also sent off.
"It's just an accumulation of things. It's football," Mbappe told reporters.
"You have to learn when playing in this kind of club to let it go because it's like that everytime so if I get upset every weekend, I'm going to take several reds so we have to be above it.
"No, I do not regret it. And if it was again, so I will do it again.
"And I will apologise to supporters and everyone but I cannot tolerate these kinds of gestures."
Mbappe was booked in the first half for dissent after he kicked the ball away at a Nimes free-kick and then aimed words at referee Jerome Brisard.
Neymar spoke to Mbappe shortly afterwards, appearing to calm the teenager after an opening period in which he was subjected to numerous heavy challenges.
Mbappe hit out at the tackle from Savanier that provoked him in the 94th minute, saying: "Where we play the ball, there are no problems, but here there is no intention to play the ball.
"But well, it doesn't matter, I will go to the commission and I will go to defend myself.
"I think it has no place on a field of football but it does not matter, the referee has made a choice and, as I said, we must rise above it.
"Paris Saint-Germain is above that, we are above that."