Your headaches are most likely caused by an infection in your maxillary sinus cavity. You may have a oro-antral communication (leak from your sinuses into your mouth) -- Sometimes when wisdom teeth are removed, the roots may go into your sinuses - The hole left is supposed to heal/close by itself, sometimes they don't. If there is a hole is can be easily "Closed" by an oral surgeon. Good luck!
Post extraction headache may be associated with infection, change of occlusion , or irrevelant of masticatory system. Seeing an orofacial pain specialist is advised.