Hi Jessicarobin! Doing cardio 6 days a week is fine but if you are finding it hard to get more definition in your upper body, you may want to convert one cardio day to a circuit day so that you get weights in with your cardio workout (ie: Boot Camp). If you are still having a hard time seeing more definition, you may need to convert that one day of cardio to a total body weight training instead of a circuit workout (ie: MIS, Power Hour, Muscle Endurance).
Or you could try doing a 4 week rotation of the PS series, followed by a three week rotation of S&H series and then return to the PS series for another 4 weeks (that would bring you in right at 77 days from now). Also, while on the PS series, you would do it twice per week every other week (so that would be on week two and on week four whenever doing the PS series). You would still do your cardio workouts each week in addition to these weight rotations but on the weeks that you are doubling up on the PS series, I would suggest only doing 3 to 4 cardio workouts.
Of course, clean eating is a must for optimal results.
Good luck and be sure to post your question in the Open Discussion forum to get feedback from the others. Take Care!