There are certain smells that I do notice. Strangely enough, there was one about 10 years ago that made me flashback to when I was about 5 years old and having what was likely my first crohn's attack. I had actually forgotten about being sick as a child until that smell came back. Cat has a point - if it isn't a normal odour for you and you don't have an obvious dietary reason, it means that your body is processing differently for some reason. Something has changed, and it is probably worth looking into.