Head measuring small?

Christy • Mommy of Hunter, Madalynn, and our angel baby Blake born sleeping at 39w. Our rainbow baby girl is due July 15, 2016!
Yesterday at my growth scan, they told me my little princess' head is measuring small. They didn't say by how long or seemed concerned. Just wondering if anyone else is or has gone through the same?? I am 28w 4d.