My last period was February 6 2017, I was supposed to get my period on the 8th of march I'm now on…

My last period was February 6 2017, I was supposed to get my period on the 8th of march I'm now on cycle day 48 . I have pcos but sense I been on metformin it has been regular this is the first in a year that it has been this late I've took a pregnancy test but it was negative is their still a chance I could be pregnant