There are certain books and sources of info that state anything under 16hrs of light a day can cause the plant to begin flowering.....shorter light cycle so it makes me wonder if:

1. Is your plant already flowering due to less light hours or is the plant showing preflowers?

2. If your plant is already flowering and IS a female....your yield is going to be pretty small due to the lack of veg time.

3. Is the plant a male or female?

4. Has the plant begun flowering or not?

Without photos......I'm afraid I won't be much help here.