Could I be pregnant?

Okay so last month I got my period 10/12/14 and I was expecting my period to come between the 8 and the 11 of this month, I keep track of my periods with glow and <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period tracker</a> and according to <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period tracker</a> I was supposed to start 11/10/14 and according to glow I was supposed to start 11/09/14, so point is, I haven't started my period I'm between 5 and 6 days late. I don't really have any pregnancy symptoms I took a test 11/13/14 but it came back negative. I don't have any of the usual signs of starting my period like cramping or bloating like I normally would and I'm always regular give or take a day. Could I be pregnant, and when would be the right time to test?