Highest Chance of Pregnacy is 33%???

Kristin • Trying for #2!
Hello everyone!! I'm new to Glow and as I was browsing through my calendar I noticed that every day there's a percentage of pregnancy. Today is not during my fertile week, so the chances of getting pregnant are 3%, but as I went forward, the highest percentage is only 33%???? Does anyone know why that number is so low??