feeb - sorry i can't help you, i'm in the same boat, and could have asked exactly teh same question. I can't explain what is going on, my temps have been a rollercoaster for the past week and I was bed ridden all last week, the days i actually felt better my temps rose, i would have thought it was the other way around, so I'm just as clueless as you as to what is going on.
good luck hon and I hope its not just the flu playing with your temp, but something else bfp wishes to you