I'm so confused... Help

Alrighty,

So I was supposed to start my period 12 days ago. After day 7 of not getting my period, I started to worry. And now I got up this morning to brown discharge and very, very light blood.. like it was almost pink..

Can somebody help me? I'm a little worried that something is wrong... Should I go see a doctor? Or is this something to do with lifestyle changes?