I was a few days late for my period and now that i have it, its a brown bleeding and not very heavy. i have never had this before... what could it be?

Hormonal blip: It is probably nothing bad, just an odd month, late ovulation, hormone thing. I would just watch and see what happens next month. You'll probably be back to normal.

Normal variation: Could be normal variation. Sometimes periods come early or late and sometimes start light. However if your period is much lighter than usual then there is a chance of pregnancy, so then check a pregnancy test.