Not sure how to read charts?

I’m kind of new to charting and as advised by another member downloaded the fertility friend app. I got a peak smiley face on the 11th August on the clear blue advanced. I do take my temp roughly the same time each morning, give or take 10 minutes, and I don’t get up or move ot sit up etc. I have a fairly expensive thermometer as well so it should work normally. I always wait for the thermometer to make its little sound before taking it out from under my tongue.

Any advise is welcome. I have previously tempted a few years ago when I conceived my son who is turning 3 soon, and the chart normally would match ovulation to the peak opk day, but that was a long time ago and bodies change, so who knows.