router subscribe calls multiple time : <p>I have this code</p>

<pre><code>ngOnInit() {
    this.router.events.subscribe((val) =&gt; {
        if (this.router.url.indexOf('page') &gt; -1) {
            let Id = this.activedRoute.snapshot.params['Id'];
            this.busy = this.httpCall.get('/pub/page/GetPageById/' + Id)
                .subscribe(
                data =&gt; {
                    this.pages = &lt;Page[]&gt;data;
                });

            console.log(Id);    
        }
    });

}
</code></pre>

<p>and when I navigate to <code>domain.com/#/en/page/13</code> it logs <code>13</code>. Then when I navigate to the page which id is 27 it says:
<code>13 13 27</code>. when I navigate back to 13: <code>27 27 13</code>. What's wrong?</p>
