Implantation bleeding or?

Soo three days before my period I started spotting I thought nothing of it, because I just assumed I was going to start early, but the spotting never got heavier like my periods normally do and only lasted for two days. There were no clots, it was pink then red and then pink and I barely had to wear a pad which isn't the norm for me. So my question is if it could have been implantation bleeding how long do I wait to test?