7 days late & getting a neg. could I be pregnant?

Emma • 23/ Mum of one / girlfriend of one
Hey guys.
I'd love some advice
I'm seven days late and I'm always regular at a 31 day cycle.
I'm very teary
Hungry 
Soreish boobs
Stiffness all over
Less hair coming out than usual 
And I went to the docs and they wouldn't do bloods for another week but the urine test was neg.
Is it possible I'm still pregnant? 
Help
 If not, what could be causing the late period