I started with an XY chromosome set, but because those gonads didn't develop and produced no hormones, my body kept the Y chromosome but just didn't develop male parts.
So my body stuck along the default path of looking fully female on the outside, but having no functional female reproductive parts on the inside.
The medical world advised that the only option was for me to live as female, which I did for seven years.
Before the final operation (castration) was due at age 16, I backed out, and was allowed to go back to a male role. I was so happy to be so unique, and I was so happy I'd have some weapon up my sleeve to prove my hated high school biology teacher wrong during her lessons on biological sex.
That means that I was born externally female, with a uterus and fallopian tubes, but with unformed ovaries.
Genetically, however, I have XY (male) chromosomes. There was no difference in me as a child, no ambiguous genitalia as an immediate alert, so I only found out once I failed to start puberty.
Person A: I don’t identify with the normal boy girl stereotypes because technically I’m something different. How old were you when you realized you were intersex? My mom started getting concerned that I had no period or breast development, so that was when the first doctor's appointment happened.