Clomid... ovulation tests!!! Confused..

So this is my first month on clomid and also using opks.. i tested on CD9 got a low reading and CD11 got a peak reading so i BD for the last few nights, because im not sure about how the tests or clomid works i decided on sunday monday and this morning to do the tests again... sunday low fertility, monday high and today peak?? Has this happened to anyone else before!!! Please could anyone advise me..