Me *puts up her hand*
In my first cycle charting I had flat temps for a while, was suggested i had a flat battery etc but it was all new and not that.
In the following months ive noticed that sometimes i stay with only very slight temperature changes BUT i can notice this with a 2 decimal point, without I would be flat lining.
I think a 2 decimal ones is around the $15 to $20 mark.

Good Luck with your charting Suz