Damn dude your plants are looking good, about double the size of the last images you posted, good job, the spots could be a number of things, splashed water, over watering or if you're using nutes might want to ease up on them, I'm only watering most of my plants through the hole veg stage.
If everything goes well I'm going to start flowering tomorrow tue or wed, I soo can't wait, it's going to be fun to watch the changes, I put one of my suspected males in a seperate closet and am giving it 12/12 to spead up the process. I feel once I do this and get a positive id then I will be safe to say that the rest are male, then I can be done with them and focus on me girls.
Good job on your grow, you're definitely off to a good start, I'm going to enjoy watching your progress.