Am I pregnant

Natasha
So I am 6 days past my period (in fact completely past my period tome) and have done about 4 tests 1 being clear blue and the other three were first response, only one came up with a vvvvvvfl and it was the first I did? 
I have spaced them out and still nothing, I have no sypmotons for AF but have a few things that's could be pregnancy like gassy and very tired... But why is it not showing? 
Am I pregnant?