@PTVinny_30 ,
I agree with starrsgirl and NewTestament. As backwards as it may seem, having a good pre-req GPA (and just good grades/test scores in general) will help you get into PT school more than being a PTA will. Because so few applicants have been to PTA schools, but all applicants have to take the same pre-reqs, this is what the PT schools have to use as a basis of comparison.
You really just need to put all your grades in a spreadsheet and do the math. Put PTCAS grade points for each class in one column (ie. 4.0 for A+/A, 3.7 for A-, 3.3 for B+, 3.0 for B, etc. etc.). Then put the number of credits the class was worth in the next column. Then you obviously multiply each and divide by the total number of credits to get the GPA. Once you have your whole life's coursework entered in this format, you can easily just plug more classes in or change numbers around and see what sort of PTCAS GPA you end up with. You can also select out the pre-reqs and calculate that GPA separately and then see where retakes put you, etc.
Additionally, you would do well to call each school you are interested in applying to and find out what their procedure for retakes is. Some may do direct grade replacement, some may average the two, etc. Then you can actually know with accuracy what each of these schools will ultimately be determining your pre-req GPA to be. Find out what their average pre-req GPA for admitted applicants has been the past couple of years. Once you have done all the math and collected all this data, you can easily select the schools at which your ultimate pre-req GPA (based on predicted future grades in retakes, additional classes, etc) will be the closest to the school's average.