Sex during fertile window, too dangerous?

Hi ladies,

This guy and I started a long distance relationship a month ago. He plans to visit me next week to spend a few days together before he leaves to the military in a few weeks, I won't see him until July. I really want to have sex with him but I will be on my fertile window those exact days and the thought of accidentally getting pregnant terrifies me but at the same time I want to be with him. I was thinking of taking the next day pill just to be extra safe.

Would it be too risky or stupid to have sex regardless?