What Causes Delay Of Periods, Brown Discharge Followed By Red Spotting?

I'm two weeks late for my period. Im alwaya regular. I had neg urine tests just over a week late. yesterday I saw brown discharge in the morning when i wiped. by the end of the day i was spotting red blood. this morning still spoting but there is more red blood when i wipe (seems like a really light period which ive never had, always really heavy right from the beginning). no cramps (i usually stay home from work because of cramps) is this a miscarriage? am i even pregnant?