Hi Jenny,
I hope everything goes OK for you.
When my 3 girls were pregnant, they did all the same things as before, they were never interested in the mineral blocks, and I had never tried cuttlefish. They do build up the nest and stock on supplies before they give birth, and the belly's got very large so you tell who was pregnant or not, couldn't tell you if the teats were showing before hand or not. didn't notice any strange sounds, but they did live outdoors. When it was time to give birth, then she would stay in the nest box I'm sure she only did this just before the birth, i would notice that I had only seen the other two for a week, and then you would hear the babies, I always waited a week then i just peeked in with out taking them out, check how many and then leave her to it.
She will stay with the babies, nearly all the time at first, even if i called her she didn't come out at all unless i moved the nest, only coming out for a short time to feed and drink. The others females would all sleep in the nest box even with new babies, only the male had to sleep in a different nest box.
Also made it a little difficult as all 3 could be pregnant at the same time, so the babies would all be in the same nest box, with different sizes, depending on how far apart they were born. It was possible to have 1month old and new born together.
I just left them to it and made sure they all had plenty of extra food.
fingers crossed, really all you can do is wait and see.
Sarah x x x