I think my cat is about to give birth?

our cat is pacing, yowling, meowing, and hissing when you touch her hard, large stomach. we found her earlier, so we dont know how long shes been pregnant. shes currently in our garage with the lights off with a cardboard box with a towel, food and water. shes forsure in labor, but what do we exepect ? help please. we want to keep all the kittens and mother healthy. will she reject the kittens if we touch them with a towel ?