
I never had any success checking temp & gave up long ago.
I had a bitch who was determined she was going to have her first litter under the gooseberry bush - I was determined she wasn't. In the end I shut her in her whelping cage & when the 1st puppy appeared, she gave me such a look of horror "TOLD you I wanted to go out" She was horrified to have made such a mess INDOORS!!! Fortunately, instinct soon kicked in & she was a wonderful mum.
If she's huffing & puffing, sounds like Molly's getting ready - altho' it might take 24 hours +
Good Luck!