There really is no need to transfer to a secondary (this is fairly outdated advice) unless one is adding other ingredients (fruit, spices/herbs, wild yeast/bacteria, oak, dry hops, etc). Leaving the beer on the primary yeast cake is really no problem up to 6 wks. Not that average beers need to be left that long, but rather a time frame for you to work from.
The issue with transferring beer to secondary too soon can leave an unfinished fermentation and excessive fermentation byproducts (diacetyl, acetaldehyde, etc) that may still need to be cleaned up the yeast.
With that being said, depending on which yeast strain you used, your beer is most likely done fermenting. The only way to really know is take a hydrometer sample and see where your Final Gravity is.