I had arthroscopic knee surgery to fix a lateral meniscus tear. But I was doing a squat and felt popping right there could I have torn my meniscus?

Yes. Yes, it is possible that you tore your meniscus again, particularly if it was not yet fully healed. There are other possibilities as well. I would certainly let your surgeon know.
How does it feel? Go by your symptoms. How does it feel? Unless it's swollen, you have an effusion, mechanical symptoms like locking or catching and it's affecting your gait then just see how it evolves.