Is it normal for implants to be moving/sliding/sloshing?

Hello, it is not uncommon for patients to report the sensations you are having in the early postoperative healing phase.  However, ongoing followup with your plastic surgeon is required to ensure you are healing normally.

The sloshing sound is air and fluid moving about within your implants and/or in the space outside breasts.  As the air is absorbed, both  sources of this sound will stop.  The wiggly/popping sensation will stop as the tissues heal around the implant.  Be sure to have firm support, day and night, until these symptoms subside.  Talk with your plastic surgeon if any of these symptoms seem to be getting worse.

I have had a number of patients that notice the "sloshing" / sliding symptoms you are describing, and it seems to be particularly seen, in my experience, with saline breast implants because they are "fluid filled".  Did you have saline breast augmentation? Movement or popping could really be seen with any breast implant device depending on the amount of soft tissue laxity and how "loose" the pocket is.  It may also be more common when implants are "closer to the surface" and placed above the muscle.  I have also seen sensation recovery take a bit longer when implants are placed above the muscle (in my experience).   I would recommend that you follow up with your board-certified plastic surgeon and describe your symptoms.  I hope this helps!