If there are no eggs--and you're certain--that's a pretty good indication that the queen is no longer there, or is not able to lay for some reason--no available space, for example. If you're checking for eggs, in my experience you have to check every possible egg laying place. The white blob you mention is royal jelly, and there is quite likely a larva floating on top of it. In the first photos it's not completely clear what I'm seeing--are those the cells you're talking about? They could be emergency queen cells, or drone cells-the angle isn't quite right. A clear photo or two of the capped queen cells would really help. If they are nicely formed cells, it's possible the hive did swarm, or there is a supersedure in progress. If they are more like emergency cells, then the queen was probably disabled or didn't survive for some reason, and they are now trying to replace her.
It's hard to know when the queen cells were capped, but it could be up to 8 days before a queen emerges, then usually around 10-14 days before she will start laying (could be less or more depending on weather and queen health). So in 18 - 22 days you could see eggs again.
It is really surprising how much can happen in two weeks if a flow is on.