Is it ok to feel my implant/muscle moving?

Yes it is quite common when breast implants are placed beneath the chest muscle to feel the muscle and the implant moving as you move your arms and upper extremities.This is a good thing for its the muscle motion of the pectoralis muscle that may help keep your breast implants often the future.

Yes, it is quite common to feel breast implants/muscle moving after breast augmentation surgery. This may occur in the short or longer term. Best wishes.

Since the implant was placed under the muscle, it would be normal to feel a sense of motion as the arm is moved since that makes the muscle glide over the implants. The implant can also move inside of its pocket. The feeling that you have is most likely normal. I would suggest however, that you speak with your plastic surgeon and express your concerns. Your surgeon will know if this is a shaped or round implant and if the pocket was loose or tight and therefore can better answer this question. Best of luck to you