How to check Trigger is fired or not

How to check Trigger is fired or not ?

create table temp(n varchar2(1000), n1 date);

After that create the following procedure:--

CREATE OR REPLACE PROCEDURE trace_error(Msg varchar2) IS
pragma autonomous_transaction;
BEGIN
insert into temp Values(Msg, SYSDATE);
commit;
end;
/

Then call this procedure in u r trigger like the following..

trace_error('Executing trigger');

we can call whole trigger at different places like 
trace_error('Executing trigger1');
trace_error('Executing trigger2');
.... and so on

then check till where the code is executing in temp table by using 
select * from temp;