I have brown descharge before my normal menstration and its normal to me but this time is only brown discharge and I thought I'm going to have my normal flow in the nextday but its not there's no blood and my brown discharge stop on 3days I am just worried f I'm pregnant or what can someone give me an advce

It might be from pregnancy, or might be an off period. If pregnancy is a possibility for you, try a pregnancy test. If negative, give it another week or so and try another test if still no period.