Fixing Uneven Breasts After Breast Augmentation?

Thank you for the question. The breast asymmetry that you are referring is commonly experienced, early in the postoperative period, after breast augmentation surgery. Often, breast implants “settle” at different rates. Of course, online consultants will not be able to  reassure you adequately;  your plastic surgeon, after in person examination will be your best resource for advice and/or reassurance.   Ultimately, I think that only time will tell whether the breast symmetry will improve over the course of the first several months after the procedure was performed.
 Of course, generally speaking, patient should be aware that absolute symmetry of the breasts is rarely present before or after surgery;  hopefully, the degree of breast asymmetry that you experience in the long-term will  not be bothersome.  My patients have to tolerate me saying:  “sisters, not twins” or "breasts are like snowflakes, each one pretty, but different” during each visit.
For precise answers to questions regarding returning to exercise, you may wish to request an earlier than  already scheduled follow-up with your plastic surgeon.
Best wishes.

Your post-operative asymmetry is probably related to unrecognized and untreated breast sag. This appears to be present on both sides. The left breast appears to have more sag than the right side. Optimal results following cosmetic breast surgery are dependent upon an accurate diagnosis of the problem. Although you have bilateral breast hypoplasia which has been treated, your breast sag has not been addressed. Without treatment of this problem breast symmetry is not possible.
Although, the position and size of your breast implants are areas of concern, this does not appear to be a major problem. These problems can easily be addressed by revising the breast pockets and exchanging implants. The type of implant used would have a minor impact, relatively speaking, compared to the issue of breast sag.
Revisional surgery will be necessary to correct this deformity. This would most likely require a left sided breast lift and possibly a right sided procedure as well for symmetry. Discuss your concerns with your plastic surgeon. Your surgeon has specific knowledge about your past procedure and will be able to utilize this information to hopefully solve your problem.

There is still swelling at 4-6 weeks and the breasts may look uneven because of the swelling.   If swelling  was indeed perceived later on, then I think a breast lift would be appropriate for the patient shown.