Pollenation doesnt need to happen to produce a seed, a fried on mine gets a few seeds every year from an all clone grow, temperature change, big changes in humidity, breaks in the plant, reverting from flower back to veg and then flower again are all examples of how a plant can be stressed and possibly produce seeds. Generally speaking, and as best as my memory is I recall stress seeds are more likely to be feminized than a pollinated seed from a male, something like 90% fem vs. A 50/50 shot. You may not find any more, which makes me believe your plant stressed at some point, not a bad thing if you got good buds. I'm doing my first autos this year, so everything I've stated is based on my experience with photo plants, guessing autos have similar attributes in a lot of ways.
