Problem with objects colliding and IsSleeping (C#)

So I have a problem with one of my exploding enemies. The enemy first moves to a position that is set through an array, when it reaches the position the enemy will stay still and I use an if statement and ask “if the enemy == is sleeping”. If it is a timer will start to countdown, when it reaches 0 the enemy will explode!

Now the problem is that there are other enemies that collide with the enemy when it is stationary, this makes the timer stutter since enemy is not “sleeping”, since moves a little bit every time an object touches it!

What is the best way to solve this problem? I still want collision on the enemy even when it is stationary, but how could I make it so that the enemy is still stationary even though an object collides with it?

Here’s the code:

using UnityEngine;
   using System.Collections;
   public class EnemyExplodeScript : MonoBehaviour {
       //private Transform target;
       public Transform[] moveToPoints;
       //public GameObject explodingEnemy;
       public Transform explodingEnemyTransform;
       int movePoint = 0; 
       public float speed;
       public float explodeTimer = 3.0f;
       public Rigidbody2D enemyMove;
       void Start () 
           //Find the which points the enemy should follow in the array
           moveToPoints[0] = GameObject.Find("MoveRightUp").transform;
           moveToPoints[1] = GameObject.Find("MoveLeftDown").transform;
           moveToPoints[2] = GameObject.Find("MoveRightDown").transform;
           moveToPoints[3] = GameObject.Find("MoveRightUp").transform;
           moveToPoints[4] = GameObject.Find("MoveMiddle").transform;
           //Set where the enemy should go with the array
           movePoint = Random.Range(0, moveToPoints.Length);
       void Update () 
           // Speed and time 
           float step = speed * Time.deltaTime;
           //Get the enemy moving
           transform.Translate (Vector3.MoveTowards (transform.position, moveToPoints[movePoint].position, step) - transform.position);
           //**Check if the enemy is stationary**
               //Start timer 
               explodeTimer -= Time.deltaTime;
           //After 3 seconds destroy object
           if(explodeTimer <= 0.0f)

Use a bool? The first time it becomes stationary store it in a variable - something like hasBecomeStill - then check that it isSleeping as well as hasBecomeStill is equal to true.