Implantation or period starting

Kaylee

Hello everyone so I was suppose to start my period yesterday. However didn’t. Last week I had cramping in my back side figuring it was pms symptoms but I never know. Today took a pregnancy test and had light pink spotting well throughout the day it quit like literally nothing at all. Now I’m having belly cramps and back cramps. Went to the restroom and have light pink blood again. Is it implantation bleeding? Or my period.