Ovulation confirm by scan CD 11 but positive opk cd 17

[Marshm]

Hi, I'm new here, ttc for 10 months (already have DS 5yo), had a fertility scan done CD 11 and they could see that I had already ovulated this month from the corpus luteum. I'm not sure why but I did a opk today CD 17 and it's a positive. Any on have any ideas why this is? So confusing, surely opk is wrong?

Do a pregnancy test - OPKs can pick up the pregnancy hormone.

How sure are they that you had ovulated? Do you usually ovulate before CD11?

Bfn on Hpt (figured too early anyway as only 7dpo so think will retest again Thursday ish?) During the scan she said she could see where the egg had come out from and corpus luteum which only happens after you've ovulated. I've only done opks for a few months as didn't want to get too obsessive both time positive day 15. I have really irregular cycles though, range from 22-34. I thought maybe pcos but apparently at scan all looked normal.

Hi sorry to jump on but l had something similar I came of the depo injection last may and got referred for a pelvic fertility scan in February as AF had not returned . The sonographer actually told me I was ovulating there and then I asked how she could tell she said the size of the follicle meant an egg was being released. I came home and tested with the clear blue digital ovulation test and was negative, the next day I had a flashy face and on the third day I had the static smiley. This also confused me as the way she spoke was as if it was happening right that moment but then for me to not get the positive test till 3 days later made me wonder which is more accurate xx