Ovulation

Hey ladies, so is anyone else confused about ovulating? I don’t know when it will happen even with the tracker apps. Glow says I should ovulate today, day 13 of my cycle. But the I did a logged a negative first response ovulation yes in this app and it changed my ovulation date to the 15th day.

Then I started looking into first response ovulation tests, they said I should take the average date of my last 3 cycles to determine when I should start taking the tests, so in doing that they said should start taking tests tomorrow.

Other apps such as flo and another one said I should ovulate on the 10th day of my cycle.

Am I doing something wrong?