It has been months after ingrown toenail and it's still not healed. could it be infected?

Ingrown toenail: Ingrown toenails that are not treated correctly have a tendency to become infected. You should see your podiatrist for further evaluation.

If in doubt see Doc.: Possible signs of having an ingrown nail may include: pain increased redness, swelling, bleeding, tightness or drainage at the nail margins. If pain does not improve, or you develop signs of infection, get it evaluated by a professional.

Its possible: I would return to the doctor for a follow up or get a second opinion. It should be healed by now. You need to be evaluated for infection or poor circulation. If you are diabetic, your sugar needs to be well controlled to heal as well.