Check if datapump session is running or not

On OS level type following:

ps -eaf | grep impdp
ps -eaf | grep expdp

ON database level:

set linesize 300
col JOB_NAME format A20
col DATAPUMP_SESSIONS format 999
col JOB_MODE format A10
col OPERATION format A10
select * from dba_datapump_jobs;

or

select to_char(sysdate,'YYYY-MM-DD HH24:MI:SS') "DATE", s.program, s.sid,
    s.status, s.username, d.job_name, p.spid, s.serial#, p.pid
    from v$session s, v$process p, dba_datapump_sessions d
   where p.addr=s.paddr and s.saddr=d.saddr;

or

select sid, serial#, sofar, totalwork from v$session_longops;
select sid, serial# from v$session s, dba_datapump_sessions d where s.saddr = d.saddr;