Plants look fine don't worry all at once they will swell it happens normaly towards the 6 week onwards but they look good get the light realy close now few inces of the tops with fans at either side to cool the heat the light ammits.
Look perfectly normal to me too for that stage You got a long way to go yet so relax and enjoy watching them swell. Take tyke's advice too and get that HPS close as you can. Fans should do the job but just test by placing the back of your hand above the buds and if you're not feeling heat you're OK.
Yes mate, looking OK, they can seem to be slow growing when you constantly look at them. It's good to take a pic every week so you know they are coming on.
But it will be more than 3 weeks to mature properly.