Fluid build up after abdominoplasty. When should I be concerned?

Five weeks ago today I got a Fleur de Lis surgery done. It removed almost 9lbs of excess skin. I had two drains in after surgery, one was removed after two weeks and then other three. However, since the second drain was removed two weeks ago, a lot of fluid has built up in my lower abdomen.Tomorrow, I will be going in to have excess fluid drained with a needle. This time, the area protrudes out more then before. My surgeon doesn't seemed too concerned but I am. Do I need another drain put in?