dude... you could flower now... that wouldn't be a problem... but seeing as how you have a space problem, i might suggest tying them down... LST (low stress training). It's way too late to top... and if you're gonna tie them, give them another 4-7 days before you flower.
but on another note, your leaves look a little bit droopy... how often do you water? what's the temperature of the room? other than those two things... i can't think of anything else that could be wrong...