I always start my period on time. same day every month, now all i have is brown discharge. is this normal?

Might be: First thing i would say is: check to make sure you aren't pregnant. If not, then it may just reflect some minor hormonal changes in your body over the past month, but if your periods become excessively heavy, or start coming at irregular intervals (especially if you are bleeding every 3 weeks or more often), then you should see a gyn to evaluate what is going on.