I'm going to be the heretic here but here goes.
First, I may be missing something, but I don't see where you state your procedure! I will assume since everyone is assuming (and we know what happens when you assume) that you did have a tt.
I tend to leave drains in a long time. I also see this not infrequently, without any ill effects. I will also say that I am meticulous in regards to hemostasis. At about 10 days or so, any clots under the flap start to liquify and will tend to drain.
As long as you are otherwise doing well and your ps is pleased with your progress, I think it is likely OK.
As you can see, there are many ways to treat the same situation.
sek