I first had symptoms of the herniated disc in the fall of 2003. In 2004 I did the series of 3 epidural injections for the neck and they worked relatively well

and lasted through the end of 2005. The pain came back and I just finished a second series of 3 epidural injections without as much success in pain relief

so I see a surgeon on Tuesday.
The epidural injection on Wednesday could lead to two more injections. Many doctors use a series of 3, one every two weeks. The shot you will get Wednesday may not 'kick in' until about 3 days later. So the first day you may really know if the shot is working at all for you is about Saturday. Again, keep in mind that many pain mgmt doctors will do the full series of 3 to see if you have good results (unless you were to have any adverse affects from the injections which I didn't have).
I only wish the second set of injections had worked well for me the second time as it did the first. I'd much rather do the shots 2x a year than have the surgery (which I'm likely having this summer).
Keep in touch and let us know how you are doing.