Your leaves are fairly dark, not bad dark but on the darker side. This is good as it means you been giving a proper amount of nitrogen, at this stage your plant will start to use less nitrogen and more phosphorus, potassium. So I would suggest slowing down on the nitrogen when feeding, it's very easy to get a nitrogen toxicity at this stage in the plants life. When the plant is developing the buds they want more phosphorus and potassium, too much nitrogen will make for leafy buds and the plant will focus on leaf production not bud production. Do a little reading/research on reducing nitrogen mid flower stage, Google,/YouTube has a lot of info on this.