2 days of spotting, 10 & 11 DPO...implantation bleeding?

My first baby just turned one and we just started TTC #2. Granted, my cycles are not 100% back to normal yet, but who knows, my cycles might just be different now. So long story short, DPO 10 and 11, I had some spotting, which I thought was my period starting early. But today, 12 DPO, nothing. And a negative pregnancy test. My period is due in the next few days (although still a little irregular). Last pregnancy I had no implantation bleeding and a positive pregnancy test at 9 DPO.

Any suggestions? Can anyone with multiple pregnancies tell me if their early signs were different from pregnancy to pregnancy?