Your comma is correct. It does make a difference whether or not you put it there though.
For example:
“eats, shoots and leaves” means exactly what you think.
“eats, shoots (like a gun), and leaves (exits the area).
Brits do not add a comma after and, but in American English, we do. (which I don’t understand why the Brits don’t..)
The comma placement changes the whole meaning.
I remember comma usage from my second quarter class of Freshman English, Winter, 1968.
From the Czar of Russia to the offical in a Russian jail.
Pardoned impossible, to be sent to Siberia
Pardoned, impossible to be sent to Siberia
But the real “eats shoots and leaves” talks about the panda’s diet.
“Eats, shoots and leaves” and “Eats, shoots, and leaves” mean exactly the same thing. The panda had a bite to eat, then shot the gun and then left the scene.
It’s the comma after “Eats” that changes the meaning. Not the second optional comma.