When Bella whelped last week I was anxiously awaiting just as you are. I kept wondering does this mean she is close? When she started I had no doubt that it was time. Somehow instincts take over and I knew it was time. Her behavior was completely different. She always wanted to be with me but when the time came she literally would not leave, kept trying to hide under my arm or behind my back. She NEVER wanted in her whelping box but she started taking her Ducky (favorite toy) inside and she turned her nose to ANY food.
I hope your girl goes a bit longer before having the pups. Good Luck it can be an amazing experience