Hitting nose 3 months post rhinoplasty - will it affect my final look?

No, this is unlikely to negatively impact your results, but if you're concerned, I recommend following up with your surgeon. Your nose and surrounding areas are going to be swollen for a while and you should be consulting the surgeon that performed the procedure but give yourself some time before going back in so some of it can subside. It can take up to a year for final results.
Sincerely,
Philip J. Miller, MD, FACS Double Board Certified Facial Plastic Surgeon

It is unlikely a light hit to the nose 3 months after surgery did any damage.  However, if you have concerns it is best to discuss these with your surgeon.

Hello and thank you for your question. From your description, it sounds as if the trauma nose was not significant and it should not affect the final result. However, if you have ongoing concerns, please get it checked over by your surgeon.