My baby just had kittens 3 weeks ago, it was her first litter. The afternoon before she started following me around, meowing at me endlessly. If I sat down for even a second she was in my lap, looking up at me and meowing. It was similar to how she acts when I've forgotten to fill the food bowl. Just MEEEEEEOOOOOWING. About 3-4 hours before the kittens came she started having discharge, she left smears of it all over me and every once in a while I had to wipe a glob of it off her tail. At bedtime she jumped up in bed with me and something similar to a human woman's water breaking happened, I think. It was a clear liquid, not thick at all, just...well, water-like, I suppose, and there was ALOT of it. She jumped down while I tended to the mess, and half an hour later we heard the first kitten cry. She didn't make any noise during the first one, but she did make one short yowling sound with each of the following ones. I had put together a box for her previously but she didn't go in it to give birth. I put the kittens inside it afterward though and she still uses it. As far as the mess...believe it or not, even though there was quite a bit of blood on my cream-colored carpet, she licked it all clean. Not even a tiny stain left.
I know all cats are different, but I hope this helps. Good luck.