Two weeks early period?

Agnes

A week after my last period stopped I began to bleed again. I did take a plan b pill so I don’t if that could be it. It lasted for 4 days and it was as heavy as my normal period. Now I’m supposed to get my period if I don’t count the 4 days. I’m a week late but I’m not sure if the bleeding I had counted as a period or not. Does anyone know what that could be?