Cycle day 1 : day your spot or day you have full flow ?

Ananya.
I spot few days before actual flow . Had sex on 6 day of cycle ( considering actual flow as cd1 ) but if cd1 shud be day of spotting then on 10 th day had intercourse . Which will put me closer to my fertile time . 
​I am having sharp breast pain and light spotting 6 days after the deed , hence curious