Any advice on leaving a seroma untreated?

I have a relatively small pooch right above my mini TT incision, 2.5 weeks post opp. When I push on it, I can see/feel water swishing around. I went to see my PS five days ago, and she said she didn't see the need to drain it, and that it would resolve on its own. Her perspective is that draining it would be invasive, and potentially nothing would come out. It has stayed the same for the last five days with no improvement. Just wondering if other doctors would also leave it alone?