Trying ❤

my boyfriend came inside twice on the first day of my fertility window (according to <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a>) 
we plan on going again today, but i'm wondering how accurate <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a> is due to the fact other sites say fertility is 72 hours or maybe i read them wrong ??? 
help 😂