FR Planned Should Husband do this Day 1 or Cycle or after my period as usually O between Days 14/16?

Hi All

Just wondering on this as I usually O between Days 14-16, my periods are often light and end after 3 days and I thought FR was best for 7-10 days? Please advise x

if you O between CD 14-16, I'd have him start FR on CD 7.