Why does my throat and nose smell?

Yesterday at work i was doing a lot cleaning smelly like drains etc and that is where i thought the smell was coming from. It was the first time i had smelled anything so awful at work! It wasn't until i got home i realised that the smell was still in my nose. Thinking it may have been a bit of dirty water had got into my nostril i washed it out. Last night i noticed the smell was actually coming from my throat too! It's not through lack of brushing as i brush at least 3 times a day and gargle mouthwash too so it is a bit of mystery! please help !!!!