Still possible?

Alli
Last period 11.29.14
Have irregular periods but always get one between 24-30 days. 
Glow said period 12.24, nothing. No spotting. Cramps but nothing else. 
Tested today: BFN
Still a chance I could be pregnant?? 
My period could just be late...but I'm wondering if there's still a shot? I think no.