I have had months were I lightly spotted for a couple of days before AF came. If you are going to start charting do not count spoting as CD1. CD1 does not start until your 1st day of actual AF flow.
Here is a link to the chart I use if you wanted:
http://www.nfpandmore.org/Chart.pdf
And here is a link to "Natural Family Planning: The Complete Approach" manual so you will know what you are doing. Chapter 6 is about BF, charting , and a return to fertility PP.
*Fingers crossed* That this really is AF so you will have a better chance at getting pg