Honey, empathy is not about having gone through the same thing, it's more about connecting to the feeling.
I've trained as a Doula, mostly because I kind of already was one anyway. Even if I'm not working as one yet, I hear (and used to hear before transition and before Doula training) lots of stories about periods, ovulation, pregnancy, dilation (the other kind), childbirth, breastfeeding, menopause, and everything else that you can think of. I guess cis women feel some energy in me and that's why they've always opened up to me about those things.
I have a friend who sells mooncups, and I've even sold a few for her! I'm actually considering taking that up. I'm an advocate for them already, as well as for breastfeeding, natural and home childbirth when appropriate, and other things, without my credibility ever being put to question.
You are not phony, Grace. You are a woman, and women have a strong tendency to be empathic, even with situations they haven't lived.
Hugs!