After getting level 20 I was rewarded with 20 ultra balls (among other stuff). I assume this would have been like with the great balls, which unlocked them and allowed you to collect them from pokestops.
However after getting about 30-50 pokestops after hitting level 20, I have yet to get a single ultra ball, am I just incredibly unlucky?
Is it possible to get ultra balls from pokestops or is it going to be a pay to get item like lures and lucky eggs?