Honestly, it's hard to say! I think you have at least 4-5 weeks left, for it looks like its still bud building and your Tri's looks their just now beginning to develop. Get a jewellers scope, and lol closely at your trichomes, because that is how you would tell especially when your plant is finished there's a certain percentage of clear cloudy and Amber you're going to want. Happy growing and good luck, grow big.