Could I be pregnant?

harly1626
I use 2 apps to track my cycles. I use <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period tracker</a> and that one said i was suppose to start my period yesterday. Glow is telling me i am suppose to start today. No signs of AF. I usually have pre-AF symptoms and nothing this month. I have been on and off nauceous for 2 weeks. 
I took a HPT this past tuesday and it was negative. Could have been to early. 
Anyways, could i be pregnant?