Okay, I’ll answer your questions
1. Discharge is in your underwear before your period, it’s usually white and sticky. This doesn’t necessarily mean your getting your period soon though, as I have had ischarge for two years and don’t have my period
2.You know your getting breasts when your chest starts to get bigger. Oftentimes it’s showing through shirt and you might want a bra. But you don’t need to wear a bra if it makes you uncomfortable, like I have breasts but bras are extremely uncomfortable for me so I don’t wear them
3. I don’t have much expiernce with this, but form what I’ve heard the actual period doesn’t hurt, but cramps can.