I was slightly asymmetrical before surgery, and still am after. The left was a little fuller and lower than the right, and now the right implant sits a little higher (see my review for full story).
I came across this answer from Dr. Rick Lentz that basically says what happened to me is fairly common, and I'm wondering how many other women fit this profile? Did your doctor adjust for the difference?
"All women have asymmetry of their breast with 80% of the time the left breast is lower and bigger than the right. There for the right breast is usually a bit higher and when the breast are enlarged with implants the right implant must be placed a little lower than the natural lower breast crease. This is usually quite tight and tens to push the implant up higher than on the left side. In oder to counter this tendency you can put a strap across the top of the higher breast which with time will hopefully stretch out the new pocket and allow for more symmetry. This is usually effective for up to 6-8 weeks but once the pocket has healed you will need further surgery. I often put the patient in a stretchy bra and then lift the cup of the bra over the top of the high ridding breast. The more time this is in place the better the chance to correct the problem. When breast are even than the two pockets are the same and you can stop the treatment."