Woah I did not know that! That’s actually really interesting and is definitely an interesting way to look at Tessa’s situation!
Yeah I mean it is weird, and maybe Tessa is like people with violet eyes, but what I always thought was that Tessa did get her period: you could get your period but have other problems that prevent you from getting pregnant, like (might be a bad example, but I do love that show) in the show Friends Monica had her period but had to adopt because her uterus was “hostile” and she could not have children. So what I thought was Tessa probably did get her period before she knew she was a warlock, thinking she could most likely have kids, but once she realized that she was a warlock and heard that warlocks can’t have kids she just assumed she couldn’t either. She probably assumed something else was wrong. I mean who knows maybe she wasn’t even thinking about it this way, but just thought warlocks have different rules that apply to them in these matters in general! I don’t know, that’s just what I think but obviously there’s more than one idea that works, and the people with violet eyes idea is really interesting :)