Well.. "sciatic nerve" is a little bit misleading. There is no actual sciatic nerve/sciatica, it's just a term to describe pain into your legs. Also, there's more than one nerve, at every level (vertebrae) there are nerves that come out on either side. These branches go all the way down and innervate different areas. Depending on the state of ones back, either a disc (what cushions your vertebrae) or one of the joints can press on part of a nerve. Generally when there's arthritis/DDD in one's back, it's a combination of both because one leads to the other. (this is a very simplified explanation, by the way)
Given your description I would guess that L4-L5 and/or L5-S1 are involved. Of course this is a safe guess on my part, something like 85% of bulges and herniations occur there.
So if you get an MRI in the future, don't be surprised to hear that you have bulging discs in this area. All you can do is take care of your back. If you are starting down the path of DDD, you can't stop it - it's part of life and aging.
You can however slow down damage somewhat and prevent yourself from really messing things up.
I suggest you, and anyone else with back issues, read up a little on how the spine is made up, how the nerves run, and common problems with it. Look at anatomy diagrams..
This is a very basic site with some info about back problems http://www.spine-health.com/
Also, before anyone suggests it or you get the idea yourself. Don't go to a chiropractor, you don't know how your back looks right now. If you have a very bulging disc any "adjustments" could rupture or tear it.
Clicking around and noticed this - http://www.spine-health.com/blog/pai...ommon-mistakes
Some very good advice there.
Personally I have a very good spine specialist, while my back has been better for treatment, if it gets worse I can always call him and get an appointment.