you could just naturally have a higher level of testosterone than the average "biological" female! if you're planning on going on hormones, then your doctor will order blood tests. these will show your current hormone levels and may give answers. otherwise, if it's not causing physical harm, pain, or distress, then embrace it!

Variation in bodies and hormone levels is completely normal! There are cis men with high, feminine voices and cis women with deep voices, it's just a cool part of human variation ^-^ That said, if you feel concerned that there's a health issue at play here, definitely follow your instincts. They are there for a reason :)

Sex isn't really a binary in such a cookie cutter way, humans only have like 15% sexual dimphorism and most of it comes down to genetics. Plenty of people, really most people honestly, have both male and female traits to some degree. Pre t I had pretty much the same body hair areas (chest, stomach, feet, hands, a tiny bit on my back) and a small mustache that all got thicker and darker on T. I've also always had masculine hands and feet as well as fairly broad shoulders, even my ring and index finger proportion fall on the Male category. I was a DD pre top surgery despite all of this because of my moms genetics. I suspect but havent confirmed PCOS has a hand some of it but even with that a lot of these traits just came from my parents. My mother also has masculine hands and feet, I also still have very wide and curvy hips because that's a gene I actually got strongly from both sides of my family, although my body shape in general matches my dad's closest, so that feminine trait is present in both male and female family members all over my family!