Two weeks ago, my hive of packaged bees (installed April 10th) was going like gang busters I had two full sized boxes with lots of new and capped brood, and really good amount of stores, and some drone brood. So I put on a medium super , all the frames were just foundation, no drawn comb, and after asking a few questions of some very experienced beeks I added a queen excluder to build up the stores with the thought of always being able to add boxes below the excluder so the hive could increase in size. I had no intention of robbing this year, so next year I would have a strong established colony. There was still room in the lower two boxes for expansion, so I had no real worries. Today I did my first inspection since putting on the medium super and the queen excluder. They did not draw any new comb in the super and Both lower boxes have ZERO brood, capped or otherwise. I didn't see the queen, though that doesn't mean much, and I'm pretty sure I didn't have a swarm since I still have a fairly large population. There are some queen cups, but they are empty, and I did notice a couple of capped drone cells. There are cells that appear to have a brown substance, and I wondered if this was capped brood that has been laid by workers.
So what to do? Do I acquire a new queen and put her in? Do I let things be?? No clue here and now am a bit worried.