How long do I keep it in?

Taylor • Married to the man of my dreams ❤️ 7.13.2017

So the hubby and I are TTC, and my fertile window ends in 6 days. Should we try on the highest percentage day, or all days? How long do I keep his cum inside, I know this may seem like a stupid question but I really am curious 😂 I don't want to keep it in too long and cause an infection or anything like that.