I found this plant blooming this week in Chestnut Ridge Heritage Preserve, along the banks of the South Pacolet River. It was growing at the base of a tree in the sandy soil of the river bottom. The blooms were facing down and I had to hold them up in order to get the photo.
your wild plant is called Phlox stolonifera, the creeping phlox. It is a somewhat delicate plant, and a favorite of mine. It can spread by means of its stolons, but I have never heard of it being invasive. One of our Appalachian endemics.
Dr. Steven R. Hill, Botanist, SCNPS