Will I go from 32a to 32d?

Thanks for your question. To talk about with property about what volume is best for your type of body is better a personal evaluation or at least some photos. Gummy bear implants, are great, but like i said for tel you volumes you need to be evaluated. Kind regards 

Patients often think in terms of cup size when considering augmentation. Unfortunately, devices are sized in terms of milliliters (cc) of volume. This can lead to some confusion when sizing. Additionally, it is important to remember that cup size itself is not standardized with variations from one manufacturer to another. Unfortunately, as many women can attest their cup size in an industry leader such as VS is not necessarily transferable to another brand.
Another point which is often under appreciated is that of anatomy and starting point. Any implant will add volume to the volume which is already present. The implant is additive. A particular volume will not necessarily confer the same cup size to different patients (often times it will not even confer the same cup size to different breasts in the same individual...remember they are "sisters" not "twins"). 

A general rule of thumb is that 125cc can represent somewhere between 1/2 to a full cup size increase. Smaller volume differentials (25-50cc) are typically less consequential representing a volume change of less than a shot glass. However, I have found these numbers, at least anecdotally, to be of little help. Patients often present with notions/goals which do not correlate with these sorts of sterile volumetric assessments.

When sizing patients, there are a number of useful tools including:

-3D imaging (has the added benefit of offering a volumetric analysis of the pre-operative breast)

-Breast sizers (rice bags)

-Goal photos

I also recommend that patients commit to a particular look rather than a cup size. Once a patient settles on a look that pleases them the overall cup size increase becomes less relevant.
With regards to your specific question, an A to D is a significant volume augmentation. There are physical limits to how big one can go (defined by one's anatomy). Your implant selection seems reasonable. Again, I would caution against using your cup size as a goal. Find a look you like/love and commit to that.
As always, discuss your concerns with a board certified plastic surgeon (ABPS).

It is important to realize that the ultimate breast size and shape depend upon so very many variables.  A 300 cc implant on a petite woman with a thin frame may look quite large, but that same implant in an overweight woman may be barely noticeable.  Size and shape of the result depend upon the volume of the implant, the shape of the implant, if it is over or under the muscle, your skin and its resilience, stretch marks, the degree of breast sagging, chest circumference, amount and distribution of the natural breast tissue, etc.  For this reason, it is impossible to give reliable advice based simply upon height and weight, or even photos. The only way to approach reliable predictions is with an in-person examination with a board certified plastic surgeon, the use of sizers, 3-D imaging, and most importantly, relying upon the skill, expertise, and experience of your chosen  Board-Certified Plastic surgeon. Best of luck!

Dr. SubbioBoard-Certified Plastic SurgeonNewtown Square/Philadelphia, PA