Can you give a few details? What was the OG? What's it at now?
There is no printed timetable for "how long to ferment". You ferment until it is done. The bigger the beer, the more cautious you should be about rushing it into bottles. It is done when the gravity is stable over a period of days, but as a practical matter it often pays to wait.
FWIW, I rarely bottle earlier than four weeks.
"Anything worth doing, is worth doing slowly." ~~ Mae West