Find SceneIndex out C#

Hello, im Writing a Save/Load script, and i would save the SceneIndex in the Registry using PlayerPrefs. Here The script:

 using UnityEngine;
 using System.Collections;
 
 public class SaveLoad : MonoBehaviour {
     
     public static int gold = 0;
     public static int lifepoints = 0;
 
     public bool loading;
     public bool saving;
 
     public InventoryManager invm;
     public HealthC hc;
     private SceneFader sceneFader;
 
     void Awake()
     {
         sceneFader = GetComponent<SceneFader>();
     }
 
     void Update()
     {
 
         gold = (int) invm.coin;
         lifepoints = (int)hc.lifePoints;
 
         if (loading)
         {
             ActivateLoad();
         }
         if (saving)
         {
             Save();
         }
 
     }
 
     private void ActivateLoad(){
         if(PlayerPrefs.HasKey("SaveState"))
         {
             Debug.Log("Found SaveState");
             Load();
             Debug.Log("Gold:"+gold);
             Debug.Log("Life:"+lifepoints);
         }
         else{
             Debug.Log("Load: Save");
             Save();
         }
 
         loading = false;
 
     }
     
     private void Save(){
 
         saving = false;
 
         PlayerPrefs.SetInt("SaveState", 1);
 
         PlayerPrefs.SetInt("Gold", gold);
         PlayerPrefs.SetInt("LifePoints", lifepoints);
     }
     
     private void Load(){
         gold = PlayerPrefs.GetInt("Gold", 0);
         lifepoints = PlayerPrefs.GetInt("LifePoints", 0);
 
         InventoryManager.inventory.SetItems("coin",gold);
         lifepoints = invm.initLifePoint;
 
         sceneFader.SwitchScene (2); //Here I would to replace the 2 with the saved SceneIndex (SceneFader work like the Application.LoadLevel)
     }
 }

Thank's for Idears!