I joined because I'm in a bit of a bind and was told that this was the group of people who could help me. (Just short of popping or a Vet visit to probe)
I recently purchased what was supposed to be a pre-sexed male Juvenile Albino Checkered Garter from an unnamed, (for their privacy) reputable breeder. Upon further inspection, this snake appears to be female. I contacted the breeder and told them that I think there may have been a mistake. (At the time they were only selling males) I wouldn't have contacted them but they guarantee the gender of their animals. They seem to have dismissed me outright and told me that a mistake was impossible. I sent them the same photos I'm about to share with you and have yet to receive a response.
Please let me know what you think, and sorry if this isn't the appropriate place to post.