Android : Android PendingIntent extra returns null

I'm using GCM as service for push notifications in my app. Notification is sent when new post is added, and when user clicks on notification I want my app to open activity with that new data.

This is piece of code in GCMIntentService class for adding String extra (So activty can parse JSON from newest post:

final Intent notificationIntent = new Intent(context, Info.class);
        [..]
                        String title = jsonObject.get("title").getAsString();
                        Log.d(TAG, title);
                        String pid = jsonObject.get("id").getAsString();
                        notificationIntent.putExtra("pid", pid);
                        Log.d(TAG, pid);
                    }
                });

                notificationIntent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP
                );
        PendingIntent intent = PendingIntent.getActivity(context, 0,
                notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT);

Returned PID string is good, but when i try to get my intent from activity

Sadly this piece of code:

 Intent iz = getIntent()
 pid = iz.getStringExtra("pid");

returns null.

@Override
protected void onNewIntent(Intent intent) {
    super.onNewIntent(intent);

    if (intent.getExtras() != null) {
        pid = intent.getStringExtra("pid");

    }
}

I've tried to launch it that way, but it doesnt work either.

Any ideas how to pass string to my Activity from Pending intent?

I've googled a lot, but can't I can't find solution that would work for me,.