I'm 14, today I noticed brown discharge- have I started my period? It last around 4 days?

Menstrual blood/tissue can be brown, pink, orange, light red, dark red - it's mostly about exposure to air before it comes out to where you can see it. It's nothing to worry about. Brown is just older, oxidized by oxygen in the air.

Yes it does sound like it is. Do you not have a mom or aunt or even grandmother that you live with that you can discuss these things ?