I am 3 days post-op (breast augmentation) and have a creaking sound when I move my left arm in circles. Is this normal?

The residual fluid and air around the implant are causing the sound and will ultimately resolve.  You want to be careful about a lot of arm movement this early after implantation.  You do not want to develop a hematoma.  See your plastic surgeon if this doesn't resolve in the next 2 weeks.

Yes this is a normal phenomenon, particularly within days of surgery. Audible air pockets are common, and with saline implants, some patients can actually hear fluid swishing around. If you have concerns about the degree of swelling, and particularly if the swelling is asymmetric, it is best to put in a call to your surgeon to assess and make sure you are healing properly at this point. Good luck!

Your implant sliding against adjacent moist tissues causes a friction
rub (sound) that can be felt as well as occasionally heard. This is
termed "bourdonnement" and was definitively described in the plastic
surgery literature: "Bourdonnement and other benign temporary breast
implant sounds", Annals of Plastic Surgery, Vol 43 p589, 1999. Typically
this occurs in the immediate post-operative period and resolves without
treatment in a few days to weeks. You also have fluid (serum, blood, local anesthetic, antiseptic irrigation, etc.) that is part of the surgery and this too can make sounds with arm or implant movement (the "gargling" sound your husband heard), but is distinctly different from the "creaking" you hear.The third component of  what you describe is called subcutaneous emphysema, or "air in the tissues." This is literally air that was in your breast pocket when the incisions were closed. This air, and the fluids mentioned earlier, all reabsorb and the sound, squish, and bubbles go away. Bourdonnement can take longer, as it is simply moist tissue sliding against your implants. But it always seems to go away! If bourdonnement is noted later in your recovery, it could signify a new inflammation, possibly related to a moderate trauma
to the breast tissues, or perhaps secondary to bacterial contamination such
as from dental work (controversial, but still a real occurrence). The
inflammation that causes this sound may also be related to a recent
viral illness such as chest cold or influenza.

A friction rub heard on chest auscultation with a stethoscope can be
associated with a pulmonary embolus from DVT. Late bourdonnement alone
without any other symptoms (leg pain, swelling, shortness of breath) is
NOT worrisome. Fear not--this is entirely normal for this point in your recovery, and absolutely nothing to be concerned about. Best wishes! Dr. Tholen