Sensitivity to Smells

I'm a high school English teacher who teaches mostly freshmen. I won't lie- freshmen stink, literally. I have become used to it for the most part and just keep a can of Febreeze in my desk. Today, though,  I've been super sensitive to smells. To the point, where I had to stop a student from talking and ask him to give me a second. His breath and BO smelled so bad, I thought I was going to throw up. I was telling some teacher friends at lunch and they said that it's an early sign of pregnancy. Is this true? I'm only 6 days past my peak ovulation day. Is it too soon to take a pregnancy test? I've been trying for over a year and really don't want to get my hopes up too high. I can't handle the recurring disappointment.