When performing backup with scripts its not easily possible to get the percentage complete of the running backup. This simple script will show status of current running backup on the server.

SELECT
L.NAME DBName,
R.percent_complete as [Progress%]
FROM Master.dbo.sysdatabases L Left join sys.dm_exec_requests R on L.DBID=R.Database_ID
WHERE R.Command LIKE '%BACKUP%'

Or you can change the where clause and use the following

SELECT
L.NAME DBName,
R.percent_complete as [Progress%]
FROM Master.dbo.sysdatabases L Left join sys.dm_exec_requests R on L.DBID=R.Database_ID
WHERE percent_complete > 0

If no backups are running then the query will return no data.