I agree with Heather that 3 weeks is along time. Maybe she miss informed you & was including time she possibly did with lupron or birth control. I think the longest they let anyone stim is about 10-12 days from day 1 of taking the core drugs. (gonel-f, Follistism)
The eggs grow 1-2 cm a night. I think you will be fine. Also after you trigger they will still grow. Don't worry, it sounds like your DR is got this cycle well planned!!!
Good Luck!
Well, 3 weeks is very long, so I definitely wouldn't go by that (that means she had a hard time developing eggs, which is usually not a good scenario). I think the average days of stimming is 10 days. And I assume you will continue the meds for a few more days before triggering, which means the eggs will continue to grow until the 19th, so that sounds pretty good to me! Best of luck with everything!