3 stitches in the middle would usually follow these instructions:
row 5: k3
row 6: k3
row 7: sl3
row 8: sl3
Instead of leaving a strand of 3 stitches, I am working an additional stitch with the strand. Starting in row 5. In row 13 this stitch was decreased again. The stitch only shows on the wrong side of the knitting.
The photo shows two lines created this way.
Shown with a cast-on count of 17 stitches.