Relax, I also had the interview in Charleston few weeks ago, and the officer gave me a certain day, middle of the week, when it would be updated, after the case was approved towards the end of the interview. It did update post lunch on the day I was told, and then the system kept updating very frequently and card was delivered to me in one week from the interview date. So may be a small delay due to the system/manual delay, but as the officer said approved, you are not going to see any other result. Try to breathe and start working on whatever your next plans are - getting ready for work, or travel plans etc.
I started my paperwork in April last year. USCIS is doing a good job, in managing cases. They are humans too.