seroma

I posted a couple weeks ago, but needed some more answers. I am going to my breast surgeon on Monday (she is out of town till thurs). We are going to schedule my port removal and seroma removal. It's like a sac on the right side. My surgeon did drain like 50cc of blood back in Jan, then put a drain tube in that area for 8 days, which  did fill up with blood. But a seroma is not blood, is it?  I am so worried. It's bothersome.  Any thoughts?

Shari from Michigan