Have a look at the post in October on this subject - I recall you were part of that discussion.
It isn't a high rise out of the 'normal' range you're looking for, but a rise above what has been the norm for the week you've been recording. Assuming you do as I do, which is start taking temperature a couple of times a day about 5-7 days before whelp date. If you have done this you will have a good idea at what the temperature is settled at. Give or take the natural fluctuations you get at any time, let alone when pregnant. I think I gave examples in my post.
I know people don't always find this works. I have, as has my breeder. It's a case of using it just as an additional aid. As someone with scientific training it's a method I'm happy to use, in fact I find it quite interesting to see how reliable a guide it has been for me. But, if you are only monitoring once or twice daily all the way through, then you are not going to see the changes. You will need to judge when to start increasing the monitoring. You also have to take into consideration whether your bitch actually minds a thermometer being shoved up her bum on a regular basis. Have to say that neither of mine could have given a tiddly squat, so we did it :-D