Weak Period

Heather
So my whole life I've had very heavy periods usually lasting 7 days and heavy for about atleast 4. We've been TTC for 3 months now and my period was 2 days late then it just spotted for 2 days and then nothing. I took a pregnany test thinking maybe I was pregnant but got a BFN. Should I be concerned at the change in AF? Or just how it goes sometimes?