Anyone help me work out when ovulation happened? Or has it not?!

Hey

Please help! Been ttc and had a shocker with miscarriages and d and cs

I attached my bbt chart. Can anyone help me work out when I ovulated? I got a positive opk on day 20 with fmu around 6 am. And also that evening. We dtd day 20 in the evening. Day 21 in the morning at 9.30 am then day 22 at 9.30 pm

Have I not ovulated? I’m confused why my temp isn’t higher sooner? Xxx