片段替换再次引发问题

我的活动XML

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">


    <FrameLayout
        android:id="@+id/contentFrame1"
        android:layout_width="match_parent"
        android:layout_height="match_parent"></FrameLayout>

</android.support.design.widget.CoordinatorLayout>

我有一个attachView方法,它从活动的onCreate调用

@Override
protected void attachView() {
    // Get the fragment from dagger
    getFragmentManager().
            beginTransaction().
            setCustomAnimations(R.animator.slide_up, 0, 0, R.animator.slide_down).
            replace(R.id.contentFrame1, new MatchFragment2()).
            addToBackStack("MatchFragment").
            commit();
    getFragmentManager().executePendingTransactions();

    new Handler().postDelayed(new Runnable() {
        @Override
        public void run() {
            getFragmentManager().
                    beginTransaction().
                    setCustomAnimations(R.animator.slide_up, 0, 0, R.animator.slide_down).
                    replace(R.id.contentFrame1, new VictorFragment()).
                    addToBackStack("VictorFragment").
                    commit();
            getFragmentManager().executePendingTransactions();
            getFragmentManager().getBackStackEntryCount(); //this reads 2
        }
    }, 3000);
}

VictorFragment不应该是场景中唯一存在的片段,并且从中后退应该退出活动吗?