If there is no pollen, there will be no seed. End of story. Some pollen sacks grow mid-bud, not just at the nodes. If no males in the room lately, or you haven't transported male pollen into your flower room, (on your clothes, on other plants...) then someone in your room threw-out a nanner.

With most strains, seeds need 4 weeks from pollination MINIMUM for viability. Less time than that and you'll get runts, mutants, no-show's and pipe blasters. More than that...you get a better percentage of healthy plants.