Can implantaion occur sooner when a tube is shortend I have had 8 cesarean deliveries and my sixth resulted from a ruptured uterus and burst bothtubes?

Doubtful...but. Time to implantation won't necessarily be shorter in the scenario you describe; however, I would be worried about an ectopic pregnancy (pregnancy outside the uterus) if you suffered damage to your fallopian tubes during the uterine rupture. If you get pregnant again, you should see your Ob right away to make sure the pregnancy isn't in a tube instead of the uterus. Best wishes!