Unexpected bleeding

So I had unprotected sex about 8-9 days ago, and during that time the condom broke. And he did cum inside of me. After we realized what had happened, we went and bought the pill the next day. But yesterday I started experiencing some light bleeding, kind of a pink; then through out the day, it was full on blood. It looked like period blood, and from yesterday into today; it’s been super heavy. Could it be a side-effect or the pill? Or an early period ? I already had my period on the 9th of this month. And it ended on the 12th