LIBRA GIRL NURSE
Your mum is expecting you to tell her that you have your period, but she's probably just waiting for you to make the first move. Find a quite time when she's nit busy and say something like, mum I've got something important to tell you, that will immediately get her listening. If nothing else you need supplies. A good quality pad like libra will last a number of hours, the blood soaks in to the lining of the pad so you don't change it as soon as you see blood.
Look through the website to see much more info about your period.
and yes, you can easily become pregnant, you actually could have become pregnant before your period starts as you don't know when you ovulate. If you're going to have sex, you must use condoms