@jackie421blfdgurl, I will be thinking of you on Wednesday. I can understand your apprehension and fear due to your appointment with a surgeon. This must be especially bothersome, considering your recent transplant surgery and your lengthy hospitalization. I am glad that you will be getting an early opinion and treatment because of risk of an infection.
A year after my transplant, I had to return to Mayo for a surgical procedure. It was nothing like going thru a transplant surgery. Plus with my new organs, I was healthy and recovered quickly.

Here is some information that I found about Seromas
https://www.healthgrades.com/right-care/symptoms-and-conditions/seroma
Keep in touch, and let me know what the surgeon tells you.