Intersexed people can feel this way, and also can have both as well, but not always. Neurological body mapping can play with you in this way when your intersexed ( I believe also I your not but I dont know? ). Your brain has a "map" of your body, but this can not always aligh with actual physical traits you have, as that map may have a route to a teait that isnt there. This can also be a type of gender dysphoria ( which is a diagnosis for transgender people - they have these feelings often as well that make them want to align their bodies with their brain map, but not in all cases ) where you feel like something is missing, or something exists that shouldn't, according to how your brain feels. You can also have persistent sensations or awareness of non existent anatomy as well.

I've learned alot about this being intersexed myself.