One breast swollen after possible viral infection - is this going to affect the settling of the implants or predispose to CC?

This is something that does seem to happen with no explanation. It also typically settles on its own without needing any intervention. You shouldn't be at increased risk of any complications but if you need to be reassured then I'd suggest booking an appointment with your surgeon to be examined. Best of luck! 

When concerned, it is always best to check with your surgeon. At 2 months, you are only about 50 percent settled. "Drop and fluff" refers to the fact that as the skin stretches and the muscles relax, the implants move down and out slowly – about 1 percent a day. It’ll be about six weeks before they even begin to settle down, but they’ll be close to 80 percent settled at three months. Watching their progress is like watching your hair grow. You don’t see a difference in your hair growth daily, but all of a sudden you need a haircut. 
Be patient after surgery. Give yourself a few months before making a judgment about your surgical results. You won't know the outcome until then.
Dr. Ted Eisenberg, Board Certified Plastic Surgeon and Author