Why Is My Menstruation Delayed After The First Time?

I have had clear discharge for nearly 2 years now, and i also have had under arm hair for one year and public hair for 2-3 years. I have small boobs but can fit into a A or AA bra. I am 160cm tall and weigh 6.8 stone. My mum got her period when she was 13 or 14 and I am 13.5 so when do you think I will get my first period?