Play punch animation sequentially if mouse is pressed

So if I hold down LMB I want first the right punch animation to be played and if the player is still holding, then play the left punch as well. Repeat.

I have this code. The function is called inside an if(Input.GetMouseButton(0)) statement.

When I hold down the mouse button it sometimes plays one of the animations twice (or more) in a row before the next animation plays

Code (CSharp):

1.  
2.  
3.      bool punchRight;
4.  
5.      public void punch()
6.     {
7.         if (punchRight)
8.         {
9.  
10.             GetComponent<Animator>().SetBool("LeftPunchBool", false);
11.             GetComponent<Animator>().SetBool("RightPunchBool", true);
12.  
13.  
14.             punchRight = false;
15.         }
16.  
17.         else if (!punchRight)
18.         {
19.             GetComponent<Animator>().SetBool("RightPunchBool", false);
20.             GetComponent<Animator>().SetBool("LeftPunchBool", true);
21.  
22.  
23.             punchRight = true;
24.         }
25.  
26.  
27.     }