The dd command doesn’t include any kind of output on its operations. So if you’d like to run a lengthy dd operation and monitor its status, you’ll have to resort to a trick.
killall -USR1 dd will make dd to output it’s current status.
If instead you’d like to monitor the progress continuously, you can use
watch -n 10 killall -USR1 dd instead. Replace 10 with the number of seconds between dd output reports.