Car bumber question?

I got into a minor accident today in which the front of my car just hit the the rear end of another car. There was no noticeable damage done on either car and we both drove away fine. My question is should I get my car bumber checked out cause after I came home I noticed the bumber had moved a little. I pushed it back in easily and everything else seemed fine.

So should I got to a shop and get it checked or do you think its fine.

Note:

I was only idling the car when I hit the person, so no more than 2-3 miles per hour.