ovulation problem?

I am trying to conceive as i have polycystic ovaries my doctor has given 50mg clomid. i started it last month and i ovulated on day 24. i felt symptoms like temperature rise and ovulation pain. next day my doctor did my scan and found water which showed that i have ovulated. after a week she did my progestrone test and it came back fine. now she told me to use clomid by myself for next three months. so i decided to buy some OPKS (urine tests) and started checking from day 18 till day 25 and they are all negative and i am confused about my feeling because i alwyays had high temperature and almost every day i get back pain which mix up with my lower pelvic pain. so does that mean i have not ovulated this month? is this some thing i should concern and contact my doctor to increase my medicine? or i might have ovulated earlier? as even with metformin my periods are irregular they come between 31- 37 days? i kind of have a feeling that i have ovulated on day 17 because before that i had watery discharge and then on day 17 i had clear discharge and i felt slight pain in my ovaries but it not really noticed as my doctor said i should start trying from day 18 of my cycle till day 26. my cycle started on 28th may 2011