2Sox
Observe how the bees are filling frames with honey and nectar, if there is a queen present they will leave space for her to lay in the future, if it is old brood comb they may start polishing the vacant cells.
Also if the hive is content and not what we call roaring, more noise, vacant cells, polishing then wait.
Also if you have a virgin queen and bad weather then mating flights will be delayed and so extended time to finding eggs.
No rules, just bee clues that the BK detective must access.
If you want to hurry the detective work, just add a frame of brood with eggs and in 3 days you will have the answer to whether you have a queen. QCells=no queen, no QCells=probably a queen.
Also as a hint to lock a swarm to a box, just add a frame of open brood and there is a big chance they are yours.