Implantation bleeding VS breakthrough bleeding?! HELP?

So, I believe to have ovulated on the 23rd because I was experiencing cramps on my right side near my hipbone, but we're currently NTNP (can't help but over analyze a little) so I didn't do an ovulation test. Ovia believes I ovulated on the 29th, although I don't think I did. If I ovulated when I think I did, I would be almost 9dpo I believe. That being said, I just got off the pill a month ago. I just wiped and saw the SMALLEST amount of pink blood. It wasn't a lot at all. However, I don't know if this is breakthrough bleeding? I don't know when exactly I'm due my next period (Ovia thinks the 12th of April based on when they think I ovulated, I think sooner). Can someone please explain the difference between implantation bleeding and breakthrough bleeding to me please?