Displaced spreader grafts
My suspiscion is that you are palpating areas and seeing areas along the dorsum of your nose where there is a transition between the nasal dorsal bone, the septal cartilage, and the spreader grafts. You may have not seen this slight irregularity previously due to the swelling that you had in the area but as time has gone on, it is likely a small void of either bone or cartilage. Unless you were palpating very hard in the area, you likely did not displace the spreader graft. However, spreader grafts can shift without any provocation at all. The key is that you are happy with your results. If this slight irregularity becomes more obvious, an injection of dermal filler will camouflage this irregularity quite nicely.
I suppose manipulating an area might cause displacement of a spreader graft but it is unlikely. AN exam in person may be helpful. Good luck.
Displaced spreader graft?
I guess it is possible to shift a cartilage graft with frequent manipulation; on the same token, it is possible for a graft to shift even by itself. Speak to you surgeon to figure out the nature of the problem.