I could be way overanalyzing this
You're not overanalyzing it. You're Wayyyyy overanalyzing it to a detrimental degree.
Even if you did take them back, and the pharmacy made a log of it, it would just be in their internal pharmacy 'drugs to destroy' log and wouldn't be sent to the state or anywhere else to update your records.
All they see is that you were prescribed a very small amount of a low dose pain medication once after a surgery and you picked it up. Something thousands of people do every single day.
It's not that important. You're not going to be red-flagged because your doctor/surgeon wrote a prescription and you picked it up.
You only get flagged as a drug seeker for drug-seeking behavior. That does not include picking up a small prescription for a few pain meds a doctor wrote for you after minor surgery. If it did, anyone who's ever had a root canal or tooth pulled would be flagged and the system would be useless.
100%. I've been saying it over and over. It's election season on the internet, division aplenty.