Variations of this phrase, such as "Check yo self foo!" and "Check yo self before ya wreck yo self" are also used to communicate the same message: correct your behaviour (idiot/before you get in trouble)
See also: check yo self before you wreck yo self
Isaac: "Whatever. Your math skills are mediocre at best. I bet you couldn't even prove the Pythagorean theorem with a compass and a straightedge."
Phineas: "I believe those are fighting words. Let's take this outside. I'm going to slap you silly with my pocket protector!"
Isaac: "I suggest you check yo self before you wreck yo self. I've got three of my chess club buddies backing me up and one of them takes taekwondo!"