I realized that I felt as though I had some mucus in my right nostril. I blew my nose and nothing came out so I didn't worry. A few minutes later, I noticed that when I would breathe, it sounded and felt as though I still had something in my nose. I blew my nose harder and realized that there was about half an inch of brown mucus sticking out of my nose. I had to pull it out of my nose and there was about 3 inches of brown mucus in the tissue. It basically looked similar to a slug as well as had similar consistency and was all in one piece. I've never experienced this before and it was a dark brown/slightly reddish color.

Should I be worried and what is the cause of this? This was on one nostril only and the other one is fine. Thank you.