Can anyone explain this to me?

Am

My period is suppose to arrive tomorrow, (8/30) I've had no symptoms for either AF or pregnancy, other than this....?

Normally I start spotting by now (like every month) or having something, cramping, bloating, backache...but this month, nothing...? I've taken 2 tests within the last few days, both BFN. I don't know what to think....?