I have a headache since having an impacted tooth pulled 4 days ago,only goes away for a couple hours after medicine and starts pounding again. normal?

See your dentist: It is normal to experience Some level of pain after surgical extraction of any tooth. In sever impaction cases you will experience more pain. Usually there is a seven days post-op check with your surgeon but if your pain is unbearable you need to call them. In most cases they give you antibiotics along with the pain medication. Make sure you are taking the antibiotics as directed. Hope that helps

Not uncommon: Depending on the difficulty of the extraction, post op discomfort can range from zero to severe. Not knowing your situation, it would be best for you to call your surgeon.

Not unusual: But not normal. No pain is normal. Considering your degree of discomfort, call your treating Dentist or Oral Surgeon to see if they recommend additional treatment. The greater the degree of difficulty, the more intrenched the infection, the more compromised your oral and/or general health, the greater the risk of post-surgical pain.