My period was 8 days late. On Saturday night I noticed brown and pink discharge. Sunday morning I had heavy bleeding that stopped Monday night.

Late period??? It might be just a period that lagged behind (which is fine every so often). See if happens again next month. If so, contact your gyn to discuss evaluation and treatment.
Period. it sounds like you had a normal period that was late vs a miscarriage, did you happen to check a home pregnancy test.