4 days post hematoma surgery. Is dark blood coming from incision site a good indication it is healing?

Without knowing the extent of the hematoma or what was done during the hematoma evacuation, it is hard to give sound medical advice to your question. However, if the area was extensively irrigated, some of the oozing may be from the irrigated fluid now migrating out. Also, since that blood is from the original surgery, if the hematoma was incompletely or unable to be fully evacuated during the second surgery, the oozing that you see now may be due to the breakdown that eventually occurs of the clotted blood. If you think it is truly "dark old blood" then the blood that you are seeing is just the blood that pooled from the initial surgery, however, it is probably prudent to have your plastic surgeon know what is occurring so that he/she can determine the best course of action for you.

While it isn't out of the ordinary for dark blood to be oozing after a hematoma evacuation, if it does not diminish with time, see your surgeon. This is the kind of thing that is nearly impossible to diagnose online. Best of luck.

Note: This is not formal medical advice as I have not examined you. Only a physician examining you in the office can properly counsel you on whether this is expected after your most recent procedure or if you need further management. If I understand your question correctly, you had surgery for a hematoma and now there is still dark old blood oozing? How long ago was your hematoma procedure, and what was the procedure before it that led to the hematoma? Did your doctor leave a drain in?It is not uncommon to have some venous/dark blood oozing even after a hematoma evacuation, but if it persists you need to call your doctor and be seen in the office. If you are soaking through pads, that would be concerning. When is your next appointment with the doctor?