Am I wrong??

I haven't been on here much lately but I'm sure the transgender and bathroom thing has been brought up a lot, sorry to get into it again. I didn't have strong feelings either way but I was this today and it really kinda pissed me off. If I'm right, genitals actually DONT define gender, they define sex. Gender is a social construct and to identify with a specific gender has nothing to do with the genitals one is born with. Am I wrong or is this just a horribly ignorant post?