If there is no white column when you run a test, run another test in 2 to 7 days. In the meantime, consider running a control test to ensure your Men’s Rapid Fertility system is operating correctly. If there is no white column the second time you run a test, your sperm concentration is low and you are advised to consult a physician. You can request a control solution by contacting Customer Support at (800)833-3935.