Confused need help.

{brandie ♡ rose}
In August af was 10 days late and lasted about 4 days, September it came 6 days late and lasted 3 days and was very light. It's not due til the 17th but I'm having mild cramps amd dizziness, back ache, and my boobs hurt. I tested and it came back negative could I have messed up cycles or showing false negatives? My af is usually on time and lasts 7 days