Implantation Bleeding? UPDATE

Jennifer
Hey ladies! So, I went to the bathroom and had some light pink spotting. I put a {small} tampon in. About an hour later I had to go again, and I could tell the tampon didn't have anything to absorb because it was hurting. This is what it looked like when I took it out, and when I wiped. I'm supposed to get my period 1/11. I thought it was pre-period spotting, maybe my period coming early. I'm not 100% sure when ovulated, maybe 2-3 weeks ago. I took a pregnancy test yesterday, and it was negative. I'm just wondering if this looks like it could be implantation bleeding? Or maybe just a symptom of my period coming?
** I checked my calendar and my husband and I BD on 12/18 (putting us 14 days out from when I started this weird, shirt spotting today), again on 12/20 (12 days out), and 12/27 (5 days out). We think I ovulated around 12/17-12/19. My question now is: how long from what is possibly Implantation Bleeding do I wait to take a test? Should I wait till I miss my period?