First, maybe your surgeon would consider giving you an oral steroid. Sometimes, this can short circuit an inflammatory reaction and get you onto a healing course again.
If the pain continues, a new MRI might be considered. If you do have a recurrent herniation, this can still be treated conservatively. Epidural injections can be very helpful. Continuation of a physical therapy rehab program can also be effective.
You might have a hematoma (pooling collection of blood) in the canal that mimics a recurrent herniation. This can be aspirated or if the symptoms are not too bad, will eventually resorb away.
Finally, if you do have a recurrent herniation and do undergo repeat surgery, this does not mean you will eventually need a fusion. That only is necessary about 10% of the time in a case of a second herniation (where a third herniation could occur and require a fusion).