Some tips:
Choose not to take many baths but instead shower. Bathing in a tub is fine occasionally, but by sitting in a tub full of soap is not good for your vaginal area. This can lead to irritation and yeast infections. If you notice any itching, burning, white yeasty cottage cheese looking discharge, or foul odors talk to your mom about possibly having one of these.
A good way to know when you are about to start your period, is to use a calendar. You can put a circle on the days that you begin your period and everyday that you continue to bleed. If you are embarrassed put a heart on that day instead. No one will recognize what it means but you. After keeping track for about three months, you can count the days from the time your period starts to the next time you begin bleeding. There will be a pattern. Then you can kind of estimate when your next one will begin. This will enable you to be prepared for it.
Another random tip I learned…….if you do get stains from the blood on your underwear, squirt some hydrogen peroxide on it and then rinse off. It will take out the blood and not let it stain. Just something I wish I would have known when I was a teen. I learned it at 40!