Confused with ovulation

The last few months I have had my temp drop and rise and one day of positive lh surge. This month I had not much temp drop and then a slight rise and have nearly hit lh positive but not quite. Could it just be that I missed the lh surge as didn't test in afternoon? I'm worried that I haven't ovulated this month. App has kept pushing my ovulation prediction back but I have just retested and now no lh surge so I'm very confused!

I have attached last months chart for you to see.

Please help!