Usually it will fluctuate up and down and up and down, gradually getting lower. Then it will usually stay low for a number of hours, maybe 12 or more, before climbing up to around 100 or so before whelping actually begins.
It sounds like you are getting closer.
Agree with watching all the signs.
Heidi Ho, Odie
Joy-Joy, Bear Cub, Hepsi-Pepsi
Cujo2, Karma Chameleon
Ramona the Pest, Kojak -- who loves you baby?
Tiny Tinnie, Susie's Uzzi, Kaiah -- The Baby Monster.