Progesterone level at 2dpo

Hi ladies. I am seeing a new doctor who tested my progesterone on Day 21 last cycle. I ovulated on day 19 and she said it didn’t matter dpo just wanted to see Day 21 levels 🤷‍♀️. Anyhow the results came back as 6.82 ng/mL. Which I know is low for a typical day 21 but seems normal to me since it was a late ovulation.... please let me know your thoughts.