Femm seeds come from a female plant that is in a last ditch effort to save the species. Late in flower these plants are slightly stressed in some way causing them to form a female pollen pod known as a banana. intersexual I guess.

Since males need to come out early to pollennate females . Like about two weeks into flower. To make a good seed crop. These banana's will at best only pollenate a very few flowers being sooo late in the flower process. Very high priced seeds.

The breeders have to collect banana's and keep them to pollenate plants that are about 2 to 3 weeks into flowering.

So late into flower is no big deal and you get a few femm seeds. Unless you have a sea of green and the the younger crop is right to pollenate. Very bad.

Also wash your room down inbetween just to make sure. Some think pollen last forever but it really only has a shelf life of about 2 weeks.