Too much Nitrogen will encourage foliage growth, as opposed to flower development. Just make sure there is less Nitrogen in the N-P-K, and you shouldn't have to worry about this as much.

As for transplanting, since you're so early into flowering and flower formation is minimal, now would be the best time to transplant, if you're going to. You'll likely slow growth down for a week or two, but it'll resume as the roots get acclimated to their new home. Better to go that route, than to diminish your yield because your roots have nowhere to go later in flowering.