Wisdom tooth extraction site really red on one side after 2 weeks. What should I do?

Call oral surgeon. After two weeks, the area should pretty much be healed. Something seems amiss. Let the surgeon evaluate the soft tissue.
Evaluation. To an untrained eye, what you describe as "really red" may or may not be within the normal limits of healing. Some really difficult surgical removal of wisdom teeth take somewhat longer to fully heal and return to a normal tissue color. You should have the dentist who removed your tooth take a look at it and determine whether or not any treatment is warranted.