I would suggest you study the full diet report generated with the "Your Secretor Status:" field set to "Secretor" and then with it set to "Non Secretor".
If the difference are minimal then you can probably skip the secretor status.
If you see changes that would make a difference in what you eat then you should take the test.
For me, I get more change in my SWAMI report from switching my A subtype from "A1" to "A2" then I do from switching my secretor status.
You can find out secretor status and A subtype at the same time with a blood serotype panel. I had my bloodwork done using Southwest Naturopathic Medical Clinic in Scottsdale, AZ. You do not have to actually go there. You just need a nurse to draw a small vial of blood to send to them. 480-970-0000http://www.scnm.edu/medcenter/laboratory.php
The "Serotype panel" tells you:
Lewis group (determines secretor status)
A subtype A1 or A2
as well as MM, NN, or MN