Pretty positive that I ovulated between Friday the 11th and Sunday the 13th, but nothing is happening on my FF chart.…

Pretty positive that I ovulated between Friday the 11th and Sunday the 13th, but nothing is happening on my FF chart. Starting to feel like charting is pointless ?. My flo app the chart there says I ovulated already! On CD22 which was the 12th. So any thoughts on why this app hasn't detected it yet?