I have a cold & cough and have wisdom teeth surgery in four days. No temperature. Is it safe for me to go ahead with it or should I postpone?

Call. Call the dentist with whom you are scheduled and discuss this issue.
Postpone... Wisdom teeth surgery is elective and better performed under sedation or general anesthesia so you can stay still. For these reasons, it is advisable to postpone. Of course, ask your oral surgeon for individual specific adivce.