ddis a command-line utility for Unix and Unix-like operating systems whose primary purpose is to convert and copy files. -wiki
dd is very convenient but by default we cannot monitor the progress.
Here is the simple way to check dd progress.
Just open new terminal and command,
$ sudo kill -USR1 $(pgrep ^dd)
If you want regular update of dd progress,
$ watch -n30 'sudo kill -USR1 $(pgrep ^dd)'
By 30 seconds (-nSEC) it will update you dd progress automatically.