now I dont know the strain your growing ..
but I grow Indicans and they take about 8 weeks to flower ..
I usually add some Bat guano powder at week 3-4 (NPK: 2/15/2%) the high P help the buds grow at this stages so you get better more dense buds in the end .. so don't worry ..
just remember the most important grow advice .. less is more ...
don't over do it .. better to give it a mild solution or some clean water in between nuts ..
find your own way .. its a learn by doing process to read your plants .. and no strain is the same ..
but you can get a good basic picture by reading a few guids and do some research before adding stuff to your plants ..
this is a good place:
http://www.420magazine.com/forums/frequently-asked-questions/83112-how-grow-cannabis-everything-you-need-know.html