LOL

flower for way longer than 3 weeks

unless you know the strain you gotta read the plant to tell when it is ready... the quickest finishing strains go about 45 days or just over 6 weeks... the average harvest window is 6-8 weeks, longer if you have a highly sativa dominant plant.. which it doesnt look like you do

wait until your 6th week of flowering to start looking for signs of maturity on your buds