Does anyone know what could cause my bbt to jump around so much? Take temp same time every morn, noted if taken early or late due to waking before or after alarm, or if sick or anything. Dont drink alcohol much, but my temp went down not up if i did drink. I use Ovuview to chart and it seems i am ovulating. I want to know why it could be varying so much, and some of my low temps (mid 35 area), seem to be really low compared to what sites say it should be. Some sites have said that thyroid problems can cause this, i havent been diagnosed with anything like this, should I see a doctor?