The only way to really tell is tail ligaments...I have had does not udder up until after they freshen, no mucous, no physical signs except they start caving in on their sides and the kids are aligning themselves up to give birth. Figure out wher ethe tail ligs are and when they are gone, you'll have kids on teh floor usually within 12 hours. I always have a "kidding" pen....when they ahve their babies leave them to bond for 3-4 days and then introduce them into the rest of the herd. A few sniffs and they are o.k. Most new mama's are very protective anyways so she will keep her babies safe. They usually don't even want to leave them to eat too busy tending to their little ones. You will just have to know your goat....more vocal, stand offish, sunk in, etc. You never really know if your goat is pregnant unless you test. I did not test this year, and I have one doe open. As far as uddering up, for some it happens within 24 hours they fill up and their udder is actually shiney. Others it is a process..don't rely on udders though....make sure she is not leaking too....you don't want mastitis. strut her out a bit to relieve the pressure.
