Losing weight after breast reduction?

I am having a breast reduction in 7 days. Before the surgery I was planning on being my goal weight. I don't plan on loosing too much weight, I am 5'1 and 117. My goal weight is between 105-110. I'm an asymmetrical C cup going down to I hope a smaller B. My biggest worry is that they are going to be saggy when I reach my goal weight. I did think about waiting until I reached my goal weight but I am turning 21 soon and I'm tired of my asymmetrical chest getting in the way. Thanks for your time.