Each body is different. I never noticed it until my brother started teasing me, because I started getting arm pit hair long before I got my period. I was so embarrased, but brothers can be nasty at times. It is normal for the body to show changes and you may ovulate before you even get your period. Every one is unique in their development
It's usually that you start your period first, but all girls start at different times, so it could be any order.
I got it like 4 years before my period