Hi Anpur & LPEAR
With regard to CD21 progesterone levels I wanted to add the information about the tests that I have gleaned last year from having them done each month, plus my own research and that of my different consultants. There is loads of information out there on forums, and I've scanned through much of it, with an optimistic mind and sometimes clutching at straws

wanting to believe I have ovulated when I probably wasn't.
CD21 is the cycle day for testing progesterone based on the assumption that you ovulated on or around CD14. Like LPEAR says, if she ovulated on CD17, then her Progesterone Test should be done 7 days after that, not on CD21 of that particular cycle.
LPEAR - A level under 10 means that you *may* still have ovulated but it is highly unlikely as it is at the lower end of the scale.
Between 10 and 20 means that ovulation is possible, but most consultants want to see levels over 20 before they would be able to say it was "confirmed". (Of course if you ovulated later than CD14 and had the test on CD21 then levels still may be low).
On a "medicated cycle" where you use Clomid or Fermara or similar, they really want to see levels in excess 30.
I had a level of 21 one month and they wouldn't confirm that I ovulated, just that I might've done, so the test isn't the best way of telling. As Maria says, the Follicle tracking scan is the best way to tell if you're ovulating.
Hope this helps
