When i blowed my nose, i found blue threads in the nasal dishcharge. what does this indicate?

Unclear: If something like this occurs again, it would be important to put it in a medicine cup or other container and show your physician. It could possibly be blood clot or infectious material, or even foreign material. Nothing "typical" would look like that in my experience. Hope that helps.

Inhaled some lint?: Your nose hairs help to trap debris when you breathe in, perhaps you were around some dust or lint with something blue in it. I bet if you think about it you could figure out what it was.