It is completely normal for saliva to have a red tinge in the first post-operative days. In the event that, contrary to expectations, bleeding starts again, place a gauze bandage on the wound, if need be a fresh handkerchief (no cotton wool, no paper tissues) and bite firmly so that the material is pressed on the wound. You should not lie down but sit and continue to cool. If the bleeding doesn't stop, medical attention is required. On no account should you rinse your mouth or continually spit.