Do you like this app for pregnancy???

So last cycle I was 3 days late due to stress. Im Usually right on with 28 day cycle. Now we’re going to TTC this week but my <a href="">ovulation calculator</a> seems to be a little off... anyone else experience this??? I know I’ll listen to my body as to when I ovulate. Just curious if anyone else has this issue with the app being a little off..? Thanks!