How can one know if a clot formed after a tooth extraction?

Are you bleeding?: If you aren't bleeding, then you formed a clot. If you're asking because you're worried about "dry socket, " you should stop worrying. Aside from smoking habits, there's very little you can do to cause or prevent "dry socket" and it has little to do with with the clot anyway. Unfortunately, lots of myth and misinformation about this has been passed on from patients and dentists alike.

Bleeding stops: After a tooth is removed there is some bleeding that occurs. The bleeding stops by the formation of a blood clot.