funkbunny - Welcome aboard.
Have you ever tried charting you temperature to pinpoint your ovulation or if you do ovulate.
Look at the fertility friend site and it will help you set up a chart. Believe me, it is great. I have just started our TTC journey for #4, and really thought I knew my body so well, boy was I wrong. I have learnt so much in the past month by charting my cycle.
The ladies in here are just so valuable to me, if you don't know or understand something you can guarantee someone will know the answer.
Good luck, you are so in the right place..