How accurate are websites that display the shutter counts on DSLRs?
Not sure if you know about gPhoto2, it can read shutter speed off your camera. I did it with my 7D.
Shutter activation count or shutter speed
I use Opanda EXIF viewer. It is a freeware. I believe all these software read the same field, so those # should be accurate. On my Nikon D7000, it is accurate.
You had your camera for 3 years. If you have only taken only 4000 photos, then you took only 110 photos per month. That seems too low.
On my unit, upgrading the firmware does not reset the shutter count. The other poster speculated or claim he heard this. I don't think that is possible. Otherwise people who are selling their used camera will just do a firmware upgrade and end up with a "newer" unit with low shutter count.