as u said ur periods are very consistent and so this may be for the first time ..for your delayed periods.. as its 11 days late till now ..better u go for pregnancy
test and check the status and if u have no doubt then u can even wait for one more cycle and nothing to worry ..
as this may be due to hormonal
disturbance due to some mental stress or iron deficiency
burning sensation may be due to gastritis
which is again a symptom of stress in u ..
u can take antacid
like pantop on empty stomache to get relieved of this symptom..
so u can wait for some more days for ur next cycle..