How to fix program that asks User if they want to re-run it again?

Question

in this program it is suppose to act as if anyone can type a number (to represent a class period), and the program will return what class I have in that period. I'm pretty sure my switch and cases are correct, but for some reason, I can't get a re-run to work, it is constantly glitching. The overall goal for this program is to have it ask the user what number they want to enter, have them enter the number, return the class period, and then ask them if they would like to enter another class period (yes/no) and either end the program or continue on. Any ideas of help on that? I'm really stuck. Thanks

//import scanner
import java.util.Scanner;
import java.text.*;
import java.util.Random;

//declare variables and methods (make class "schedule" since there are multiple files)
class Main {
  Scanner scan = new Scanner(System.in);
  int period;
  String response;
  boolean runSchedule = true;

  public void runProgram(){
    while (runSchedule){
      //allow user to input number to represent class
      System.out.println("Please enter any number 1-8 and the class period at that time will print out: ");
      period = scan.nextInt();
      askUser();


      //using switch, case, and breaks for each class on the schedule
        switch (period){
          case 1:
            System.out.println("Precalculus");
            break;
          case 2:
            System.out.println("Java");
            break;
          case 3:
            System.out.println("Honors Chinese");
            break;
          case 4:
            System.out.println("Gym");
            break;
          case 5:
            System.out.println("English");
            break;
          case 6:
            System.out.println("AP World History");
            break;
          case 7:
            System.out.println("AP Physics 1");
            break;
          case 8:
            System.out.println("Music");
            break;
          //this is a default incase user enters number not 1-8 
          default:
            System.out.println("Make sure to select a number 1 through 8 to be able to see class schedule!");
            
        }
    }
  }

  public void askUser(){
    System.out.println("\nDo you want to enter another class period? yes or no: ");
    response = scan.nextLine();
    if (response.equalsIgnoreCase("yes")){
      runSchedule = true;
    }
    else{
      runSchedule = false;
    }
  }

public static void main(String[] args) {
  Main prog = new Main();
  prog.runProgram();
  }
}