UI cycling through my level select levels

When I run my unity 5 game, it quickly cycles through all of my levels, then stops on my last level. My script for starting the levels is:

 using UnityEngine;
 using System.Collections;
 using UnityEngine.SceneManagement;
 
 public class Normal : MonoBehaviour {
 
     public void Start()
     {
         OnClick();
     }
 
     void OnClick()
     {
         SceneManager.LoadScene(1);
     }
 }

I didn't change anything from the basic UI menu that Unity has provided (I guess I did though, on accident). Here is the stuff that is attached to my UI buttons: I do think there is an easier way to do this that works. I can clarify if needed. Thanks.