328 cc breast augmentation to a 100% flat chest, I want to ask you your estimates. What cup size 330 cc would give me? (Photo)

I'm sorry to hear about the concerns you are experiencing after breast surgery.There is no accurate/reliable/predictable correlation between size/profile breast implant utilized and cup size achieved. For example, I do not think that the generalizations of "200 cc equates to 1 cup" hold any validity or are helpful in any specific or practical way.  In my practice, I ask patients not to communicate their goals, or evaluate the outcome of the procedure performed, based on cup size references.
 Given that you are fresh out of surgery, it is definitely too early to evaluate the outcome of the procedure performed.You should be aware that a significant percentage of patients at the early stages of recovery will feel that they are too big or (more commonly) too small. I routinely ask my patients to wait at least 3-6 months before evaluating the end results of the breast augmentation surgery. This waiting time allows patients to (usually) physically and psychologically adapt to the new body image. 
For example, many of my patients report that as the swelling around the breast implants (for example, in the sternal area) decreases, they feel that their breasts appear more projecting. Also, in my opinion, the "drop and fluff” phenomenon does hold some validity; as breast implants “settle”, many patients feel that their breasts actually look larger. 
Although online consultants cannot predict whether or not you will be pleased with the long-term outlook, of the procedure performed, it is safe to predict that the breasts will change. Do your best to stay emotionally even keeled.
 
Best wishes for an outcome that you will be very pleased with, regardless of specific  cup size achieved.

At 4 days post op, you likely have significant healing ahead of you. I discourage patients from passing any judgements in the early post operative period as things will continue to evolve. If your concerns, persist at 4-6 months you can discuss revision.
While it is unlikely that you will get bigger with time (as swelling subsides), you will likely note an increase in projection as lower pole tissue stretches and the implants settle. Always remember..."love the look, not the cup."
As always, discuss your concerns with your board certified plastic surgeon (ABPS).

In most patients the 330 cc breast implants should increase you by 2 cup sizes. Your early in recovery and over the next 6-8 weeks your implants should have a much bigger effect on your breasts.  Of course express your concerns to your surgeon.