Seeds in feminised autoflower

Just harvested an feminised auto sour diesel and found it had a lot of seeds in it.
How could this happen? i grew it outdoors and had no males in the grow area.
Could i use these seeds?
Thankful for any ideas

You're not the only one growing in the area. Pollen can carry for miles. Somebody has a male plant going.

Harvest the seeds and store them good. Pop a few and see what you get. Could be good, could be shit. Nothing wrong with free seeds. If it wad from someone else you might end up with some semi-auto seeds. Or your plant could have hermied and diddled it self.