Period or Spotting?

I had unprotected sex when I was ovulating and my boyfriend came in me (we fucked up the cycle tracking) and I was really worried I was pregnant for a while (mood swings, nipples getting bigger, nausea, tiredness) but now I think I have my period. The only thing is, it’s about 5 days early, and I know that sometimes people get implantation spotting so I just wanted to check what you guys think. I’m gonna include a pic so it’s NSFW, but for reference I actually have really short and fairly light periods anyway so I’m finding it hard to tell. This is from all day without any pad or anything (it was only a tiny bit this morning, and then I’ve been out all day). If it helps, my period is normally very very regular.