At less than 3 weeks after breast augmentation, you and your body are still getting used to your new breast implants. Your tissue and skin are stretching and adjusting to accommodate the implants and your body is healing from the surgery. Your breasts may be recovering at different speeds, which could account for the odd movement in the left but not in the right. Some movement in breast implants is expected after breast augmentation, as it can take up to 6 months for the breast implants to completely settle into the pocket and soften. Keep paying attention to your body and wait to see how things look in a few months.
Thank you for your question and congratulations on your recent breast augmentation. You are still very early in the post-operative period and should expect to have swelling and soreness for three to six months. Shooting pains are quite common as well as different sensations in each breast. Please follow your plastic surgeons specific advice regarding your level of physical activity and use of a support bra. Hope this helps and good luck with your recovery.
This doesn't sound out of bounds for normal healing to me. I would suggest that you talk to your surgeon. You can also call the office and talk to the nurse. Pay good attention to your surgeon's instructions.