Have you done your egg pick up (EPU) yet?
If not, 19 is the number of eggs you have.
My FS (and I think most) writes the number of eggs collected on a tape and sticks it on your palm so when you wake from the anesthetic, you look at you Palm and know you how many you got
The lab will then call you a few times over the next few days to update you on the progress of the fertilization.
For me, I had 12 eggs collected, 8 fertilized but in the end there was only 4 usable embryos (1 fresh transfer and 3 more frozen) so for me it was a third
Everyone is different though.