
Always I thought 'why have I done this (to you)' with my girls, watching them waddling around during the final days. As for temperature taking, it is a guide, but for me, I count the days, from the first mating even if conception may not have taken place immediately. If mine go over by more than 2 days, then it's off to the vet. Mine would go into secondary inertia - going well and then ouch mum = shut down. That's Bassets for you (some are okay).
What you may be seeing are little ripples, the first signs of contraction. But for me again, matters not whether this is a maiden bitch or not. If she's gone over, then I'd get her at least looked at - if you go in with her, take somebody with you to either drive, or watch her. And take a box with a warm pad/covers with you and your whelping gear. And be read to pull over. Sometimes a car trip gets things going.
Are you sleeping in the whelping room with her - recommended as bitches more often than not, start whelping in the small hours.
ps I've know Jackies whelp in a matter of hours - like shelling peas and it made me sick when the girl where were living at the time, kept saying 'another has come' and then another ...... all done and dusted in no time - whereas I'd had to virtually pull our Basset puppies out.