Its good to start out with only one or two, easier to manage and not overwhelming. I took some horticulture classes at community college a few years ago, now I'm on my fifth grow, but Im definitely still learning. Did you start it in that pot? If I were you, I wouldnt worry too much about the spots, since you can't find any bugs. Keep an eye on it though. Try to keep the leaves as dry as possible when you water. Only mist lightly, and not too often. I would wait a little bit more, then transplant into a larger pot. In flowering, the plant will double in size and needs enough room for the root system to completely develop. Don't go too big, about 2 times the size of the pot it's in now. Wait to transplant until the soil is dry on top, moist underneath but not soaked. Too moist and the roots will be fragile, then break from the dirt being heavy. Give her a couple of days to adjust, then switch to 12/12 to flower.
On another note, to prevent bugs make sure your soil isn't contaminated. I've gotten fungus gnats from infected soil, and it was newly purchased too. What I do now, is bake my soil in the oven, lol. I put it in an aluminum foil drip pan thingy, at 375 degrees for about half hour, or until it drys out. Haven't had a problem with bugs since then. Just make sure it cools completely so you don't cook the roots.