I requested a check on Monday 2/7 (day after Super Bowl). It still has not been processed. I have been playing there for 5+ years and probably done about 6 check withdrawals, and it has never taken more than 2 business days to process.
I have done live chat with them every day since Fri 2/14. They keep saying the same thing that my withdrawal is under a normal review, and that it should be ready within the next 24-48 hours. A few of the chat representatives have told me that they have been swamped with withdrawal requests since the Super Bowl, and that is the reason for the delay.
Never play their but seems your hitting the panic button a little too early, considering their solid paying history with you. Worry, if you haven't got it before the end of the 4th week.