The inside of the nose can heal for two months after rhinoplasty. Anytime during that period the nose can bleed, especially if an internal crust comes off. Unless you got hit directly in the nose it is doubtful that a stitch was torn. You can use a cold pack over the eyes and cheeks and place a gauze drip pad under the nostrils. It should stop on its own or you will need to give your surgeon a call.
Bleeding can be the result of several things. Raw surfaced can bleed after manipulation. Increased blood pressure can do it too. Best to ask your surgeon or be seen by him.
There are many reasons that you may have developed bleeding from the nose. If it does not stop by lightly pinching the nose then you should contact your surgeon as soon as possible to avoid a problem.
Bleeding after rhinoplasty should be addressed by your surgeon. I would call the office.
Kenneth Hughes, MD
Los Angeles, CA