SQL & PL/SQL

I'm writing a procedure to that takes a varying number of parameters and populates a global temporary table with the results if a dynamic query. I want to know how many rows are in the GTT after the insert, done using dbms_sql.execute. Using dbms_sql.last_row_count seems to work, but the documentation: http://docs.oracle.com/cd/E11882_01/appdev.112/e25788/d_sql.htm#i1026354 says "Call this function after a FETCH_ROWS or an EXECUTE_AND_FETCH call. If called after an EXECUTE call, then the value returned is zero."

A much simplified test case is:

 
CREATE GLOBAL temporary TABLE bc_test_gtt 
  (col1 NUMBER(1)) 
ON COMMIT DELETE ROWS; 

DECLARE 
  nSqlCursor PLS_INTEGER; 
  nReturn    PLS_INTEGER; 
  sSql       VARCHAR2(100); 
BEGIN 
  sSql := 'INSERT INTO bc_test_gtt SELECT 1 FROM dual'; 
  nSqlCursor := dbms_sql.open_cursor; 

  dbms_sql.parse 
    (nSqlCursor 
    ,sSql 
    ,dbms_sql.native 
    ); 
     
  nReturn := dbms_sql.execute(nSqlCursor); 
   
  dbms_output.put_line(TO_CHAR(dbms_sql.last_row_count)||' last_row_count rows'); 
  dbms_output.put_line(TO_CHAR(SQL%ROWCOUNT)||' sql%rowcount rows'); 

  dbms_sql.close_cursor(nSqlCursor); 
END; 
/ 

1 last_row_count rows 
sql%rowcount rows 

select * from v$version; 

BANNER 
________________________________________________________________________________ 
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production 
PL/SQL Release 11.2.0.3.0 - Production 
CORE    11.2.0.3.0 ;     Production 
TNS for 64-bit Windows: Version 11.2.0.3.0 - Production 
NLSRTL Version 11.2.0.3.0 - Production 

I would like to know if it is OK to use last_row_count in this scenario? Could its behaviour change in the future, leading to misleading results. Due to the doubts I have I might have to just to SELECT COUNT(*) from bc_test_gtt; to get my result, but that seems like unnecessary use of SQL

Background: I'm storing a copy of contact information in a denormalised, cleaned up structure. When a user enters a new client in the application, my procedure will return any potential duplicates, based on the contact information that the user has entered.

Thank you,

Ben