4 days post op. Worried breast implants are too big for my frame, will they deswell and settle over the months? (photos)

Thank you for the question.  Thank you for the photo.  You are early in your post operative course. The implants will typically rise up after surgery.  They typically start to fall at one month.  They can take 6 to 12 months to get to their appropriate position and volume.  This is the "drop and fluff" phenomenon that folks are talking about.  Please follow your Plastic Surgeon's instructions.  Each Board Certified Plastic Surgeon may have their own protocol, and each patient is different.  Let them know your thoughts.   
Jeffrey J. Roth, M.D., F.A.C.S.
Board Certified Plastic Surgeon
Las Vegas Plastic Surgery

As you note, there is not a direct correlation between cup size and implant size. The size of the implants is based on a combination of a patient's goals and objectives and her anatomy. In order to provide a natural looking augmentation, the surgeon needs to evaluate many factors including soft tissue coverage, skin laxity, chest wall width, breast imprint width, the shape of the breasts and relative level of constriction to ensure that the breast implants are appropriate for your body.  It is not uncommon for women to have initial anxiety if she chose the appropriate breast size. Allow yourself six months to heal from the surgery so that the swelling subsides and you allow yourself to get used to the breast implants.

At the six month mark, review the surgery with your surgeon to understand if the surgery met your goals/objectives.