Implantation bleeding?

Just wanting to clarify the difference between implantation bleeding and a regular period. My boyfriend and I had sex on the 2nd (he came inside) and my period started on the 10th. The first two days the blood was bright red and normal. The last 3 days it was a dark burgundy and eventually brown. My period is over now but I’m just wondering if that was implantation bleeding or just old blood. Thanks in advance!