If you see a low temperature around the time you would expect your period, your period is usually on the way. In most cases, you will see your period sometime that same day or the following day.
If it is not yet close to when you would expect your period, then it is still too early to tell. A single temperature during your cycle rarely carries much meaning on its own. You are looking for patterns and trends on your chart and to do this you need to look at several temperature points along with your other fertility signs.