Subconcussive impacts do not cause symptoms. The damage from them is cumulative from tens to hundreds such those suffered during boxing, football practice or soccer heading drills.

You likely are just reacting to the surge of adrenaline from the need to dart out of the way. A startle like that can be upsetting to a recovering brain.

You do more damage with the excessive worry that the occasional bump or jar. And no, you did not do further damage to your brain.