Implantation spotting lasting 3 days?

I woke up on Friday (1/5) with some spotting and I saw spotting only twice that day then again on Saturday & Sunday (1/6 & 1/7). I have not gotten my cycle back since having my last baby. She’s 12 months old. I am unsure if this is my cycle returning or could be implantation bleeding. On 12/29 I had some low cramping (ovulation?) and we DTD on 12/30. So Friday would have been 7 DPO - right in right timing for implantation. With my first 2 pregnancies I did have implantation spotting but it was just one time not over the span of 3 days. Has anyone else had implantation spotting that lasted 3 days?