Wisdom teeth out 4 days ago. just blew my nose and a large blood clot came out. is this anything to worry about?

Shouldn't be a : Problem as long as you don't develop excessive bleeding from the extraction site.

Sinus communication: It may be the result of different pathological processes and often occurs following an extraction of the first maxillary molar. Based on examination and x-ray, a diagnosis of the communication is determined. Drug therapy and surgical procedure will solve the problem. See your surgeon for the exam.