We have a "heat" barometer over here. My 3 boys thought Grace smelled LOVELY. She was a month earlier than expected too. But I gotta trust those noses!!! They knew about a week ahead of time!
And for as pathetic and gross it may seem, dog owners need to spend some time looking at their dogs' butts. One day Grace just seemed a tiny bit swollen and there was a drop of red pee, and sure enough, she was in season a month early.