Are all cats initially female?

Okay - I know that being a parent to a 4 year old in september makes me a little nieve (how the heck do you spell that word niaeve- give up) however, I was stunned into silence at work today to find that all babies, in the early stages of pregnancy (human babies) are female until bits suddenly devlope and a recogniseable sex becomes apparent. Took me a while to get over this - however, my wife says its true - or she keeps doing between fits of laughter and not believing I did not know - is this true of all animals inc cats or is this just my lot winding me up again?
Kev
feeling a little strange knowing I may have once been female (albeit it a few weeks into my mother being pregnant with me)but this may account for why I cry at the end of the film Ghost every time.....

that is not really true. All babies APPEAR female until there "stuff" devolpes Girls and boys have different genes right from the start. SO you were always a boy!

Thank you - that makes me feel better - however, I still cry bucket at the end of ghost - soft or what!
kev
100 per cent man! - thankfully

my hubby never cries! It is nice to know at least some men have emotions!

Yeah, I think it has something to do with the X & the Y chromosome, (and I can't spell either) So, even if you don't have your parts yet, when you are first an embryo, you do have either the X or the Y, which determines your sex.

All babies are initially intersexual at the beginning of development-they have tissues that can become male or female reproductive organs (Mullerian and Wolfian ducts). However, development of male organs requires the action of testosterone, which starts a cascade of events that leads to becoming male. Female is the "default", for lack of a better word, and if nothing happens, the baby will become female, even if it has a Y (male) chromosome.

This is true for all mammals, who all have an XY gender determining system.