Pregnant?

Patient: I had brown bleeding last month in the middle of my cycle. I called my ob and she told me if i thought it was period then to start a new pack. I waited till monday and started a new pack. I am now on the last day of the sugar pill and have not started my period. I took a test two days ago and it was negative. Could i still be pregnant? Should i start a new pack tomorrow or wait till my period starts?

Doctor: