No, you do not need another MRI.
Your neuro was just being gentle and supportive when she said "we will keep an eye on it."

The lapse at Walgreens means nothing. People who don't have PCS have similar situations. They just don't blame them on PCS.

The more you just move on with your life, the less these common events will cause you anxiety.

Why are you even bringing these non-events to your neuro ? You are wasting your money and her time.