If it's really been 4 weeks (not to be confused with 10 days that FEELS like 4 weeks
), a polite phone call to inquire if they need any more information and check the status would probably be appropriate. You might have to leave a message and you might not hear back right away, but when I did mine Melissa told me to call her if I hadn't heard anything in 4 weeks.
CCWI might chime in here if he knows what the current backlog is like, but I'm sure it's slammin busy over there.