I would inquire ASAP.
My experiences from the past 6 months.
1) Sent mine for regular renewal (estimated 4-6 week) around July 15th and it was sent back on August 2nd (received August 4th)
2) Girlfriend sent her passport right before Thanksgiving and had it back before New Year's Eve
Both were sent in as a regular service, not expedited service, and both were processed and returned within 2-3 weeks so it's not a processing time issue which leads me to believe it got lost in the system or if you never got an email with a processing number it might not have ever made it there.