Help me please! Confused AF!

So this is my first month being monitored by a fertility specialist. I had a positive opk at CD 15 and a peak at CD 16. Had EWCM both days. CD 17 I went for a scan and my follicle was 25 mm and the doctor said I could ovulate at any moment. I was cramping that day as well as CD 18. Now it's CD 20 and I went for a scan today to confirm ovulation but my follicle is at 28 mm which the doctor told me means I haven't ovulated yet. I AM SO CONFUSED! I thought after an LH surge you ovulate 12-24 hrs after. I was taking my bbt until this cycle and I've always ovulated on CD 17 and my periods are always at a 28-30 day cycle. If I haven't ovulated yet what does it mean? So far all my tests have come clear. Does this mean I won't ovulate this cycle? I'm so scared I just want a baby 😭😭😭