When to start doing it during your fertile window?

Ashley
So I've heard waiting 3 days before having sex during your fertile window is a good idea, but I usually ovulate 4 days into my fertile window... So,  should we wait to have sex until like 2 days before ovulating, withhold for 3 days and have sex every day of the fertile window, only the ovulating day, what is the best thing to do? 
I'm trying pre-seed this month, and progesterone cream.