LED lighting at wrong time

Other Hardware LEDs and Multiplexing
1

Hello.
What my project is supposed to do is:
-ask for input on serial monitor (1, 2, or 3)
-then light a specific LED based on the input.

When I type "1" in the serial monitor, the red LED lights as it is supposed to, but then the green LED lights up, though it is not supposed to. I just want the red LED to blink once, and then the program should wait for additional input before blinking another light. I want the green light to only light when I enter "3" in the serial monitor.

This Link is a link to a video where I enter "1" then "2" then "3". the green light always comes on after the red and yellow.

If anyone can help, I would really appreciate it!!

here is my code:

int pin2 = 2;
int pin7 = 7;
int pin12 = 12;
int delPer = 500;
void setup()
{
  pinMode(pin2, OUTPUT);
  pinMode(pin7, OUTPUT);
  pinMode(pin12, OUTPUT);
  Serial.begin(9600);
  Serial.println("Enter 1 for red");
  Serial.println("Enter 2 for yellow");
  Serial.println("Enter 3 for green");
}

void loop()
{
  if (Serial.available())
  {
    char ch = Serial.read(); 
      if (ch == '1')
      {
      digitalWrite(pin2, HIGH);
      delay(delPer);
      digitalWrite(pin2, LOW);
      }
      
      else if (ch == '2')
      {
      digitalWrite (pin7, HIGH);
      delay(delPer);
      digitalWrite (pin7, LOW);
      }
      
      else if (ch =='3');
      {
      digitalWrite (pin12, HIGH);
      delay(delPer);
      digitalWrite (pin12, LOW);
      } 
   }   
}

Thanks again for any and all suggestions!

2

I was able to figure it out! I still don't know why the the old code wasn't working, but I changed from if/else to switch/case.

int pin2 = 2;
int pin7 = 7;
int pin12 = 12;
int delPer = 500;
void setup()
{
  pinMode(pin2, OUTPUT);
  pinMode(pin7, OUTPUT);
  pinMode(pin12, OUTPUT);
  Serial.begin(9600);
  Serial.println("Enter 1 for red");
  Serial.println("Enter 2 for yellow");
  Serial.println("Enter 3 for green");
}

void loop()
{
  if (Serial.available()>0)
  {
    char ch = Serial.read(); 
       switch(ch)
      {
      case '1':
      digitalWrite(pin2, HIGH);
      delay(delPer);
      digitalWrite(pin2, LOW);
      break;
  
      case '2':
      digitalWrite(pin7, HIGH);
      delay(delPer);
      digitalWrite(pin7, LOW);
      break;
      
      case '3':
      digitalWrite(pin12, HIGH);
      delay(delPer);
      digitalWrite(pin12, LOW);
      break;
      }
   }   
}
3

It was not working because of this line

else if (ch =='3');

The semicolon at the end essentially ends the if statement.