Notwithstanding the earlier posts, the norm in the military world is to be told by ATC to "report checks complete" during the director's feed-in to the localiser/PAR/SRA, usually 20-15nm from touch-down. Once established on the glidepath (electronic or from talkdown controller) at about 4nm you are asked "check gear".
Not uncommon to reply "delaying checks", "checks to come" or "gear to come". You won't, however, get clearance to land unless you've confirmed that the gear is down.
We got rid of "3 greens" years ago!