The key with temping is to look for trends. One off temp doesn't mean anything. My basal body temp before ovulation, for instance, is usually 96-96.8, and goes up after ovulation to 97-97.5. There's a little bit of fluctuation, but the average goes up, if that makes sense. Like I know, after years of charting, that if my temp drops below 97, I'm going to start my period that day or the next. That's the cut-off for my body.
No one's basal body temp is going to be exactly the same every single day; fluctuation is normal. Usually it's closer to 1/2 degree, though a whole degree may be possible. If you've been charting, and you got the sustained upward shift that means that you did, for sure, ovulate, then if it goes down that much, it probably means you're not pregnant. If you have not seen a sustained shift yet, then if it's fluctuating pretty regularly, you probably haven't even ovulated.
at 2:32 PM on Oct. 6, 2010