what are the usual symptoms..

hello, our baby girl Roxy, a red nose pit bull terrier, is now expecting her first litter, thanks to my fiancee who..while I was at work..decided to breed her to our other pit bull Leonidus. I wasnt thirlled about it, but it is done and over with. She is due this friday or saturday, what are soe typical symptoms of early labor? Like, how do I know she is getting ready for the birth of her puppies? I would like to, if possible, either observe the delivery myself, or have her to the vets, just to make sure everything goes smoothly. the mamma is the red nose, nd the daddy is the brindle/white pitty.