When should I start counting my DPO?

Julia
For Example: On my calendar it showed I had a 32% chance of pregnancy on the 7th and only 8% chance on the 9th but they both fall in my "window". So should I start counting from the 7th or the 9th? We didn't get to BD a lot this month but we are trying so I just wanted to know since either way I'm in my 2WW. I didn't take any ovulation tests and I tried just by checking my CM but it would fluctuate in texture and constancy so I couldn't tell by that alone and I just want to know how to further understand this app! Please and Thank you!