Implantation Bleeding?

Stacey • One boy, one girl, Two in Heaven and another on the way. Endo Warrior, Bicornuate Uterus

I am approx 11-12 DPO....CD 22. My cycles are usually 26-28 days. Today I woke up to bleeding and was pissed cause my period has never been this early...ever. But it was brown, like old blood, and stopped this morning. Nothing now just cramps. Could it be implantation?