Possibly pregnant? or false negatives??

Missed my period in August, figured it was probably stress.

Tested just in case and was negative.

Had super light spotting the first week of Sept. like only tinted pink when I wiped the the first 4 days and a little drop of blood here told there,

and a little heavier the next 4 with no clotting, and never needed more than a panty liner...

Where as I never spot and my periods are usually much heavier and last 7 days with a fair amout of clots...

Have yet to have a period this month, took a test 3 days ago and also was negative...

Could it Possibly be a false negative or any other ideas on what maybe causing this?