What kind of thermometer do you use? And do you take your temp at the same time each day? You must get at least 3 hours of uninterrupted sleep.

I found the easiest way to temp accurately was to set the alarm for some silly time in the morning like 4.30am or 5 am. Then when the alarm went, I'd pop the thermometer in, put it on the bedside table and go back to sleep again. Then check it and record my temp when I woke.

Are your AFs like clockwork. Are you on a set cycle each and every month? I found that my luteal phase (the days after O) changed according to my O date. For example, I have a pretty regular 27/28 day cycle. If I O'd on CD15, then my LP would be 13 days long. If I O'd on CD12 then my LP would be 16 days long etc etc.

And of course, it is always possible to have the occasional annovulatory cycle as well.

Hang in there, you'll be an old hand at it soon....unless you get a BFP first!

Lisa