dull mint smell in my nose

Odd question, but have you guys ever heard of something like this: I constantly have this dull mint smell in my nose. Not particularly irritating. No one else can smell it. Happens everywhere. Once in a while, the smell is gone for a bit, but returns. This has been going on for a week or so. Happened last January for a couple of weeks then went away. No change in soaps or personal stuff. Sinus discharge is clear, no other symptoms, feel fine in fact. And when I hold my breath there is a slight burning like I just ate an Altoid mint, or that I'm holding a mint under my nose. I am having a hard time telling if it's mint, but it's the closest thing I can compare it to. Mind you it's dull, but can grow stronger at random moments, and I had it a long time ago, but it disappeared. What do you think it could be? I was told it may be GERD or LPR but I don't have any of the symptoms for these things, and so my doctors don't know what it could be. I'm quite confused. Just know I don't think I'm being harmed by it, it's not hurting me. It comes in and out during the day, sometimes I smell the stuff around me, or normal smells, but other times it's just solid minty smell, and no one else can smell it.