When a question such as this arises, it is of course best to see your doctor for an examination, to rule out rupture or scarring around a breast implant. Some times breasts begin to appear firm and small. This may indicate capsular contracture, or hardening around an implant, particularly if the implants were placed above the muscle. Over time, breast tissue diminishes in a patient with a stable weight. Patients may think their implants are shrinking when in fact it is their own breast tissue. However, as native breast tissue diminishes, implants become more visible. The answer may not be to go larger, since those implants will tend to be more and more visible, more palpable, and have more rippling. The larger a given implant is in the same patient, the more these problems tend to occur. You may want to consider these variables with your doctor, as well as discussing above vs. below the muscle placement. Good luck!