can you get a positive result up to 2 weeks before due period???

Hi there,

I had a giggle with friends an was trying to prive to them that they were wrong that i wasnt pregnant to my surprise the clear blue regular test coming up with a very faint positive line.. 

I am not due for a period for at least 2 weeks.

I took a clear blue digital test today that flashed 1-2 weeks then turned to a not pregnant

Is it posible that i am pregnant?? 

Thanks for any help given