problem with pagination library

PHP Code:
function index(){        
    $this->load->model("QueryExpense_model");
    $this->load->library('pagination');

    // init params
    $limit_per_page = 1;
    $start_index = ($this->uri->segment(3)) ? $this->uri->segment(3) : 0;
    $total_records = $this->QueryExpense_model->count_all_rows_expense();
    $data['start_index'] = $start_index;

    if ($total_records > 0){

      $data["page_expense_rows"] = $this->QueryExpense_model->list_all_rows_expense($limit_per_page, $start_index);
       
      $config['base_url'] = base_url() . 'expense/index';
      $config['total_rows'] = $total_records;
      $config['per_page'] = $limit_per_page;
      $config['num_links'] = 2;
      $config['first_link'] = 'Inicio';
      $config['last_link'] = 'Último';
      $config['next_link'] = '>';
      $config['prev_link'] = '<';
       
      $this->pagination->initialize($config);
       
      // build paging links
      $data["links"] = $this->pagination->create_links();
    }            

         $this->load->view('header', $data);
         $this->load->view('expense/body');
        $this->load->view('footer');        
    }