I've yet to see a water bag before a birth but have seen several afterwards, mucus from the rear end is not always a sign of an imminent lambing. I had some that showed mucus but then nothing for a week or more. If it's a bit, half a teaspoonful that's different to a cupful.
You'll quickly find out each ewe is different and all the 'signs' it talks about in the books, I've rarely seen.
Annoying creatures at times sheep !
