1 week post, breasts look extremely SMALL after BA, will it look bigger in a month? (photos)

Congratulations on having undergone the breast augmentation procedure. Keep in mind that no one will replace your own plastic surgeon when it comes to accurate assessment, advice, and meaningful reassurance.
Generally speaking, breast implants will "drop" into the pocket that was created during surgery. The rate of breast implant "settling" may depend on factors such as size of breast implant pocket dissected, tightness of the overlying skin/muscle layers, and size of breast implant utilized. Normally, it takes about 3-6 months (for some patients longer) to see the final result.  Similarly, it takes a few months for the breasts to "soften" in most cases.  Most of my patients tell me that their breast implants feel "part of them" somewhere between 3 to 6 months after surgery was performed.
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. Patients often report that they are happier with the cleavage area once these changes occur also. 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. 
 There is definitely a physiologic and "psychological" (body image)  adaptation process that occurs, at differing rates for every patient, for patients who undergo any type of aesthetic surgery, including breast  augmentation surgery.  I would suggest continued patience and continued close follow-up with your plastic surgeon.
Best wishes for an outcome that you will be pleased with long-term.
 

he/she is telling you the truth. It will take some time for your implants to settle down into their final resting place, do not worry, it will happen. It sounds like you and your surgeon picked an implant to achieve your goals and fits your frame. 

You are only one week out from your surgery so I would recommend that you allow some time for your implants to settle and the shape to improve Make sure you follow up with your surgeon as scheduled