My nose has been acting up

Recently, whenever I tilt my head down (sweeping the floor , putting on socks, reading a book etc.) I get this funny smell in my nose. I feel a rush and it smells kind of sour, its very strange. The first time it happened I thought I was about to have a nosebleed, but I've never actually had one in my life. Maybe its the weather (its snowy out), Who knows.... has anyone else experienced this? And NO it's not me that smells shower... I bathe ;) Is it normal?