Your story sounds very similar to mine...After my c/s I also had very bad pain on my right side, however this all started a few days after the surgery. I then developed a fever because of an infection and during an ultrasounds and CT scan they found a large abscess in the lower rt. abdomen area. (I could also feel it when I pressed on my belly). They weren't sure what caused it though. It was not near the incision at all. The OB referred me to another doctor, as they thought it was my appendix.
I ended up having an appendectomy about 12 weeks postpartum and they discovered that the infection was in my right ovary/fallopian tube because they could see lots of inflammation. I also had alot of adhesions in that area, which was causing my continued pain. Then I was referred back to the OB who diagnosed it as PID, and he told me it was extremely rare to see postpartum PID. BTW, my appendix was perfectly fine (and they took it anyway!). I am not sure if PID will always cause a fever so you might do some research to see if any of your symptoms fit that description. Just a thought.
I can tell you that adhesions/scar tissue can create some discomfort. I ended up working with an Ayurvedic doctor in Bellevue, WA who helped break up the adhesions by performing deep abdominal massage, herbal supplements and told me to massage my abdomen with castor oil, which helps with inflammation.
If you are in the Seattle area, you might also try to visit with Beth Webber who specializes in pre-natal and post-natal abdominal massage. She may have some insight. Here's her website http://www.zoelotus.org/
I don't know if any of this is helpful to you, but your story did sound very familiar to mine, except your symptoms appeared much later. I hope you can figure it out, or at least find something to ease your discomfort.