Not flax....creeping phlox.

The petals aren't pinked so this is Woodland Phlox, Phlox divaricata.

Backtracking the petal comment. The petals of my divaricata look pinked sometimes. Phlox stolonifera petals are pinked and Phlox subulata petals aren't pinked. The foliage is better for ID. Phlox subulata leaves are very narrow, almost needle-like, Phlox stolonifera leaves are heavilly spatulate and Phlox divaricata leaves are narrow lanceolate to ovate.

It's probably Phlox divaricata (wild blue phlox, woodland phlox). It grows in, or near the woods in the Eastern United States.