Backfilled swarm

I hived a small swarm (2-3 pounds) that I believe was virgin led based on its size, and prolific late afternoon fanning the first three days after hiving on undrawn foundation (two weeks ago last night). Trying not to disturb them much, I've resisted the urge to poke around in there. A quick inspection on day 12 revealed no sign of a queen. They have drawn seven frames of Ritecell and back filled it with syrup and nectar. I've only see one bee carry pollen back to hive and that was the day after it was hived. The one frame I pulled near the center had maybe a dozen cells of pollen, the rest syrup.
I've read virgin led swarms cam take three or more weeks to show signs of being queenright. How much longer should I wait? It seems every time I ask a question about queens and laying, a week later it works itself out. I'll need to add another box in a couple of days. I would have thought if there was a queen in there, they would leave at least a few cells empty for her to lay in, but from what I saw there are zero cells that aren't filled. I did NOT add a frame of brood when I hived the swarm in near dark.