Im very confused..

Teresa • 28 TTC #3

We're TTC #3 and I have 3 apps going 2 tell me the highest fertility window is the 17th the other one is I think the 12th

Idk I'm honestly so confused by it all

One says this week I'm fertile the other 2 say next week

Af was from 12/3-12/6 so when is my highest chance?

The 2 are about the same the third is throwing me off can someone help me?