Would cold sore affect me having my Breast Augmentation?

Your question is not silly.  Please call your plastic surgeon for advice because each surgeon would manage this differently.  At a minimum I would suggest that you be treated with an antiviral such as acyclovir.

It is very unlikely that the presence of a cold sore will cause a delay of your surgery. Of course, your plastic surgeon will always be your best resource when it comes  to a relevant response. Best wishes for an outcome that you will be very pleased with.

Thank you for your question.  A cold sore alone should have no impact on your breast augmentation.  While you should make your surgeon aware, your surgery will likely not be delayed.